All Physical References (Paper 2)

• All volcanism begins in the mantle

• How the mantle is heated and rises

• Decompression melting and hydration melting at subduction zones

• Neutral buoyancy causing magma chambers where magma crystallises

Oppenheimer, 2011

• Mantle convection and plate tectonics work together in one system

• Upwelling of magma can create cracks in continents

• Radiometric dating shows magma is formed at different times due to recycling of former crust at subduction zones

• This occurs as slabs of the mantle sink to the core-mantle boundary where they sit in a ‘slab graveyard’ combining with thermal instabilities to form LLSVPs where plumes and mega plumes rise from

Tackley, 2000

• Mantle plume theory proposed in 1970s to explain intraplate hotspot volcanism

• Plumes begin at the core-mantle boundary and form trails as they experience partial melt

• Plumes have heads and tails, they rise due to hotter temperatures and being less dense due to chemical distinctions

• Plumes are unstable and move at different speeds and in different directions to break oceanic lithosphere and cause eruptions

Koppers et al., 2021

• Blobs form in the thermal boundary before destabilising and rising

• Once the plume reaches the Moho it gets trapped

• As the plume rises, latent heat is removed so it cools and becomes less buoyant, this can also occur due to residue below the lithosphere

Manglik & Christensen, 1997

• Plate tectonics link the surface and deep interior to allow for the exchange of elements needed for life on Earth

• The deep Earth stabilises habitability on Earth

• The main source of water on Earth comes from volcanic activities and upwelling making volcanism the main source of life

• Volcanic activity releases elements from the deep Earth that are bio-essential and creates food chains allowing for survival

• These all stop mass extinctions and support the conditions conducive to life on Earth

Wang et al., 2023

• Polymerisation of magma means it does not have a clear melting point, silicate polymers impact viscosity

• The variables of composition, pressure and volatile content combined with polymerisation mean partial melt occurs

• Crystallisation occurs in chambers, they can track changes and influence viscosity

• At subduction zones slabs sink and the water contained in the hydrated oceanic crust is expelled into the rising mantle wedge to lower melting points and promote melting

• Anomalous hotspots lead to mantle plumes up to 300 degrees hotter than the surrounding mantle

Francis & Oppenheimer, 2004

• The Gaia theory sees Earth as a global self-sustaining organism due to the holistic feedback systems regulating temperatures and gases

• AI could save the Gaia theory due to it’s intellectual powers aiding in understanding Earth’s systems and resilience mechanisms

Radford, 2019

• Aims to combine science with indigenous perspectives to allow for better conservation, mitigation and risk assessment

• Mount Ruapehu is seen as the place of Gods and the Life Force, Crate Lake supplies sustenance to the land

• The union of Father Sky and Mother Earth sees the land as the key value within the community and guards all domains of life

• Blending the scientific and indigenous knowledge can reduce social vunerability

Pardo et al., 2015

• Villagers are able to identify precursor events based on past knowledge and experiences

• The summit of the volcano on Ambae Island is seen as a sacred site so visits are forbidden as a form of hazard management

• The villagers live away from the streams to avoid flood risks and the paramount chief makes decisions in times of emergency, yet these are often miscommunicated due to political rivalries

Cronin et al., 2004

• The rights of nature has had the greatest impact in the Global South where Indigenous activism and lack of effective laws provide incentive for experimentation

• Ecuador is an example of a success

• A multi-disciplinary approach is needed to recognise where laws are needed and how they can be meaningful

Epstein et al., 2023

• The combination of sulphur and carbon outgassing from LIPs are key in impacting atmosphere and ocean circulation allowing for the survival of life on Earth

• Sulphur emissions are intense and occur in intervals to have net cooling impacts

• There are swings in climate as warmer carbon modes (the greenhouse effect) are followed by cooler sulphur modes (albedo effect) when sulphur is injected

• The swings impact hydrological cycling, weathering and ocean anoxia

• Sulphur aerosols have a shorter atmospheric residence than carbon so cannot have as longer term impact

Black et al., 2018

• Mt Pinatubo caused the largest perturbation of the century to particulate content in the stratosphere seeing temperatures drop as well as levels of stratospheric ozone

• The introduction of sulphuric acid aerosols increases planetary albedo due to more efficient scattering, they also act as condensation nuclei for clouds to reduce their size and increase secondary scattering efficiency

• Microphysical properties of aerosols determine their absorptivity, the Mt Pinatubo particles were very small so cooling dominated

• Coupling of volcanic chlorine emissions and anthropogenic CFCs caused ozone depletion

• This study allows models to be made more accurate and policy to be amended in the future to ensure greater quality of life

McCormick et al., 1995

• There is a robust link between LIPs and major environmental catastrophes which have been linked to mass extinctions, most effective links are between the Siberian Traps and the end-Permian and the Deccan Traps and the end-Creatceous

• LIPs can have direct and indirect effects through global warming, cooling, anoxia, toxic gas or metal release, acid rain, ocean acidification or oxygenation of the atmosphere

• Global warming is due to the release of isotopically light carbon gases from HVCs as well as methane emissions

• Global cooling is created through SO2 injections to the atmosphere, CO2 drawdown due to weathering of basalts and injections into the stratosphere causing volcanic winters

Ernst & Youbi, 2017

• The strongly acidic rain and global ozone collapse resulting from episodic volcanism and heating of volatile-rich Siberian rocks are possible causes for the end-Permian extinction event 

• The peak timing of marine extinctions lines up with the emplacement of the lava pile from the Siberian Traps, terrestrial extinction timing is less clear but appears to be synchronous

• Acid rain is modelled to have disfigured and stunted growth of plants in the NH as well as damaging marine ecosystems

• In the SH, depleted ozone levels led to higher levels of UV-B flux which can stunt plant growth 

• As the Siberian Traps magmatism was episodic, the fluctuations of pH and UV fluxes would have been rapid and outpace capacity for biological adaptation leading to extinction

Black et al., 2014

• Extratropical eruptions are thought to be less effective at driving large-scale surface cooling than tropical eruptions, but recent minor extratropical eruptions produce measurable impacts

• Since 750 CE extratropical eruptions have produced stronger hemispheric cooling than tropical eruptions due to the hemispheric confinement of aerosols

• There is higher cooling when aerosols are contained within one hemisphere, this overwhelms arguments for shorter lifetimes of stratospheric sulfur

• The aerosols become heavily concentrated in the NH so peak at higher values, faster and with longer term impacts

• This can aid in modelling and reconstructions of past eruptions

Toohey et al., 2019

• The communities become co-volcanic societies as the Filipino communities have become around Mount Mayon

• It has shaped human settlements through lava flows that decimate towns and force relocation, the most famous example is the 1814 eruption causing the survivors from Budiao and Cagsawa to move to Daraga

• Place names reflect the importance of the volcano such as Uson meaning a place of pyroclastic flows

• The volcano also created islands in the lowlands due to flash flooding, the micro-regions began to develop their own dialects and languages forming a sense of identity that exists today

• This also influences myths, rituals and ceremonies such as Mayon as the abode of Gugurang, the legend of Daragang Magayon or the Bugan holy figure warning of the eruption

• The Perdon practice sees women on a procession through the village for seven nights to ward off evil spirits from the volcano seeing it memorialised in ceremony 

Bankoff et al., 2021

• The Ngati Rangi indigenous tribe living on the southern flanks of Mount Ruapehu are familiar with the mood, signs and language of the mountains so have valuable knowledge to contribute to decision making 

• Knowledge has been under-utilised and tribes have not been included in decision making

• There are efforts to better recognise the knowledge, improve communications and work with local governments to improve outcomes for the tribe and local communities

Gabrielsen et al., 2017

• Sulphur emission is critical to producing strong climatic forcing, sulphur rich magmas have low sulphur solubility so very explosive eruptions tend to be silicic rather than basaltic; magmas must also be highly oxidising or highly reducing to have the highest sulphur emissions

• Eruptions must be explosive and intense enough to penetrate the stratosphere in order to stay aloft and have a significant effect on radiation

• The height of the tropopause varies being higher at the tropics meaning a more explosive eruption is needed to reach the stratosphere

• The polar vortex amplifies the global effect of tropical eruptions where atmospheric forcing limits the impact of high-latitude eruptions

• Seasonal variation is also important as a humid atmosphere is preferable to boost plumes higher into the atmosphere; the position of the ITCZ is also key as the proximity of an eruption cloud to the ITCZ can change the dispersal or aerosols, it moves north in NH summer and south in winter 

• El Nino of other climatic oscillations can also play a part

Oppenheimer, 2011

• Often the study of thermal processes within Earth is speculative as it is based on measurements made at or near the surface 

• Solar energy, the gradual deceleration of the Earth’s rotation and energy released by earthquakes are sources of energy but these only make up around 0.002% of the energy budget showing geothermal energy is the most important source

• Geothermal energy is derived in part from heat released during the early stages of the formation of the Earth 

• It is also extracted from the radioactive decay of long-lived isotope such as uranium and potassium in an exponential pattern of decay

Kearey et al., 2009

• Increasing precision of U-Pb dating a larger number of Phanerozoic boundaries making biotic crises can be correlated with LIPs, this provides backing for the use of LIPs as proxies for golden spikes

• LIPs have many impacts on the climate such as warming due to GHGs, cooling due to sulphur emissions and CO2 drawdown as well as ocean anoxia, ocean acidification, sea level changes and toxic metal input

• The precision of correlating LIPs to mass extinctions implies a causal mechanism, Proterozoic LIPs in particularly can be used to define natural boundaries

• The volume of an LIP is not the sole control on its impact, rate of effusion, abundance of pyroclastic material and volatile fluxes reaching the atmosphere are also important 

• Feedbacks play a part in magnifying environmental impacts as well as location as oceanic LIPs have smaller impacts due to the buffer effect of seawater

Ersnt et al., 2020

• Pulses of glaciation can be linked to LIP events, they can start glaciations due to cooling via SO2 injections and CO2 drawdown or end them due to GHG emissions; there is more research needed into this

• Ocean anoxia events see black shales of low or no oxygen in the deep ocean which have been linked with oceanic LIPs

• High CO2 and SO2 in the atmosphere can form acid rain in the form of carbonic and sulphuric acid as well as transferring to oceans to cause ocean acidification with the loss of calcified marine species

• The arrival of mantle plumes beneath the ocean and emplacement of oceanic plateaus causes sea level rise but as it decays sea levels fall again, continental LIPs at first form sea level falls but continental rifting than forms rises; global warming and glaciations can also affect sea water volumes and levels

• Toxic metals such as mercury can bind to clays and organic material to lead to malformation of plants and extinctions, depletion of bioessential elements and nutrients also has this effect 

• LIPs have also been linked to oxygenation of the atmosphere and ocean leading to life such as the Cambrian explosion

Ernst & Youbi, 2017

• Anthropogenic influences are robustly detected in observed SCE decrease and GHG influence is robustly detected in separation from anthropogenic aerosol and natural forcings with important hydrological and ecological impacts

• SCE decrease shifts solar flux by changing albedo feedbacks and hydrological cycles

• There is a poleward amplification of SCE sensitivity due to warming air temperature through albedo feedbacks

• Most of the late spring SCE decrease over NH from 1970-2019 is attributable to GHG influence which identifies human contributions and GHG influence as separable from other forcing

Palik & Min, 2020

• Observation sites can be used to observe snow catchment areas, rates of snowfall and depth of snow deposits

• Drifting and blowing can be measured with snow drift meters, traps, optical drift meters and radioactive tracing

• Snow depth and SWE can be found using snow stakes, temperature profiles, albedo and free water content

• Areal extents of snow cover can be estimated by ground or air surveys using satellites with long term averages being scientifically important

• Full time observation stations can be installed as well as unmanned stations using remote and telemetry systems

UNESCO et al., 1970

• The area and duration of snow cover are decreasing at 2-4 days per decade in the Arctic which impacts terrestrial ecosystems as it shows a decrease in plant cover and productivity in the last 30 years

• Duration of snow cover is projected to decrease by an addition 10-20% from current levels by mid-century and cold-season precipitation increase by 30-50%

• The Arctic is warming faster than any other region on Earth with feedbacks such as changing albedo and water vapour increase in the atmosphere being important

• Projected changes see coastal areas have fastest and largest declines and this will have implications for food sources, vegetation, habitats, marine ecosystems, water cycling, ocean acidification and atmospheric cycling

Brown et al., 2017

• Climate models suggest rain will be the dominant form of precipitation in the Arctic by 2100 due to atmospheric warming

• Arctic precipitation rates increase much faster than the global rate of 2% per degree instead at 4.5% per degree

• This will impact hydrology, climatology and eco-locality as well as leading to enhanced permafrost melting and methane emissions

Bintanja & Andry, 2017

• There is an overall tendency to decrease in several metrics of snow extremes, particularly in North America and Eurasia due to global warming

• Anthropogenically forced changes in temperature and water vapour have the potential to have major impacts on snowfall as seen in data collected from station observations, remote sensing, satellite and in situ sources

• Snow cover extent, SWE and duration of snow cover see widespread decreases in western US, North America and the Arctic

• These downwards trends are due to a combination of natural and anthropogenic forcings

Kunkel et al., 2016

• Climate change threatens to disturb warm-season water demand by altering fractions of precipitation falling as snow and timing of snowmelt, this threatens food production in basins relying on snowmelt runoff

• This will be particularly important in high-mountain Asia, central Asia, western Russia, western US and southern Andes

• Basins most at risk see 40% of irrigation demand needing to be met by new alternative water supplies under RCP4, adaption of water management and agricultural systems will be critical

Qin et al., 2020

• The timing of spring snowmelt influences patterns of hibernation and reproduction in the population of free-living Arctic ground squirrels in northern Alaska

• Findings show that with late spring snowmelt and early autumn snow melt offspring density was lower before hibernation and the shortening of the active season will compromise juvenile recruitment

Sheriff et al., 2017

• Winter tourism is threatened due to the combined effect of decreasing natural snow amounts and suitable periods for snowmaking 

• 14-25% of ski lifts may be considered in a critical situation in the near future

• Under RCP8.5 there would no longer be any snow reliable ski resorts based on natural conditions in the French Alps of Pyrenees by 2100 with only 24 projected to remain reliable and all in the Alps

Spandre et al., 2019

• Over the last two decades NH snow cover has decreased in extent by 11.7% in June from 1967 to 2010 and did not increase in any month 

• Human influence has been detected in reductions with evidence showing that human influence is extremely likely the dominant cause of observed warming since the mid C20th

• It is very likely NH snow cover will decrease during the C21st due to surface temperature rising, this will decrease by 25% under RCP8.5

IPCC, 2013

• Over the last decades global warming has led to widespread shrinking of the cryosphere with a total loss of 2.5 million km^2 of snow cover in the Arctic from 1967-2018

• Feedbacks continue to amplify global warming and surface temperature increases in the Arctic

• This has impacted terrestrial and freshwater species, animals have had to shift their range, food and water security are negatively impacted with hunting, herding, fishing and gathering practices

• Arctic residents and Indigenous peoples have had to adjust timings of activities to resort to changes in seasonality , hydropower facilities also experience changes and high mountain aesthetic and cultural aspects have been negatively impacted

• Global scale declines in snow cover extent are projected to continue to 2050, under RCP8.5 Arctic spring snow cover will decrease by 50-90%

• Floods and rain-on-snow landslides are projected to occur in new locations and river runoff will change

• There will be further upslope migration by low-elevation species, fire and hydrology regimes will be impacted, human settlements will face increased hazard risks and high mountain recreation will be negatively impacted

IPCC, 2019

• Human influence is very likely to the main driver of the global retreat of glaciers since the 1990s and has been contributing to NH spring snow cover decline since 1950

• Changes in the climate system are becoming larger in direct relation to global warming and this will amplify permafrost thawing and loss of seasonal snow cover

• The global water cycle is intensifying with earlier onset of spring snowmelt and higher peak flows

• All regions are projected to experience further decreases in snow with largest chances at 2 degrees than 1.5 degrees warming

IPCC, 2021

• Between 2007 and 2016 permafrost temperatures increased by 0.29 degrees globally, 0.19 in mountains and 0.37 in Antarctica due to polar amplification of air temperature increases

• Permafrost warming has the potential to amplify global climate change by thawing unlocking previously stored carbon and methane, this will contribute to global warming as well as having further implications for ecosystems, hydrological systems and infrastructure integrity 

• There is a lack of consistent data due to the lack of a standardised data set for temperature observations, a lack of accessible boreholes and data having gaps but the GTN-P data set contributes to reducing uncertainties

• The latent heat effect explains discrepancies seen in permafrost trends in different regions

Biskaborn et al., 2019

• Palsas and peat plateaus are permafrost landforms occurring in subarctic mires that support sensitive ecosystems with significance for vegetation, wildlife, hydrology and carbon cycling; they cover around 850 km^2 of Finmark 

• Between the 1950s and 2010s, there has been a total decrease of 33-71% in the areal extent of the landforms; it has been a continual process with largest changes in the last decade

• Environmental factors leading to the decline are not yet fully understood, but it is likely to be correlated to increases in air temperature, precipitation and snow depth in northern Scandinavia

Borge et al., 2017

• Rapid permafrost thaw in high-altitude and high-elevation areas increases hillslope susceptibility to landsliding by altering geotechnical properties of hillslopes such as reduced cohesion and increased hydraulic connectivity 

• The altered hydrology, vegetation and physical properties of annually thawed soils and bedrock will increase landslide frequency even on low angled slopes

• This will have important impacts on aquatic and terrestrial ecosystems, accelerate ancient carbon release into the atmosphere and pose risks to human settlements and infrastructure particularly in vulnerable communities 

• There is a need for further research to predict and mitigate against these hazards as well as fill in gaps in data through expansion of English-language research, long term monitoring projects and areal data collection as well as quantifying the effect on the carbon budget

Patton et al., 2019

• In recent decades, there is very high confidence that global warming has led to increased permafrost temperatures, this is averaged globally as an increase of 0.29 degrees and will release CO2 as well as destabilising high mountain slopes

• Permafrost thaw has led to ecosystem disturbances, food and water security challenges, negative impacts on human health due to release of contaminants, coastal communities being exposed to hazards and industries threatened due to flooding

• Thaw is projected to continue and will increase further in the second half of the C21st by 24% under RCP2.6 or 69% under RCP8.5 with associated carbon releases

• This will impact mountain hydrology and wildlife, decrease productivity, increase risk of wildfires as well as threatening communication and transport in overlying urban and rural areas

IPCC, 2019

• Over the last decade global warming has led to reductions in Arctic sea ice extent and thickness, it has likely decreased for all months of the year from 1979-2018 with September sea ice decreasing by 13% per decade

• Arctic sea ice has thinned with multi-year ice seeing a decline of 90%, this impacts feedbacks, mid-latitude weather and extreme wave heights 

• Many marine species have undergone shifts in range and seasonal activities due to sea ice change, Arctic net primary production has increased in ice-free waters but many species see habitat losses with cascading impacts on ecosystems

• There are positive impacts with increased ship-based transportation of goods and tourism but coastal communities are exposed to hazards as well as marine ecosystems damaged

• Arctic sea ice extent is projected to decrease further due to surface air temperature increases, at 2 degrees of warming the probability of a sea-ice free September is 10-35%

• This will impact marine animal communities, increase net primary productivity due to upwelling and stratification and impact habitats and prey of marine species

IPCC, 2019

• Proxy records are used to suggest changes in Antarctic sea ice using whaling positions, historic ice charts and direct sea-ice observations

• These conclude a substantial southwards shift in the ice -edge did occur from the 1950s to 1980s with a mid-range estimate of 2.4 degrees south 

• Regional analyses indicate the largest change occurred in the South Atlantic but there is also change detected in the Indian Ocean and Ross Sea

• This is found in accounts of whaling operations describing fleets operating on the ice-edge following it southwards as it retreated each summer whaling season

• There are many criticisms of these ideas with whaling analysis widely regarded as inaccurate

De La Mare, 2009

• Intra-regional differences in the reduction of Antarctic sea ice extent are not widely studied, whaling databases can be used to understand these changes 

• There is a reduction in sea ice occurring in the 1960s mainly in the Weddell sector which change ranging from 3 to 7.9 degrees through summer

• Whaling records are not useful for fine-scale changes but they provide evidence for a heterogenous circumpolar change in sea ice extent consistent with environmental changes detected in the Weddell sector and SH

• This has influenced the ecosystem of the Weddell Sea, particularly krill biomass

Cotte & Guinet, 2007

• Natural drivers of Arctic sea ice variability such as large explosive eruptions or cycles of oceanic circulation are poorly represented, but external forcing can explain up to a third of variability 

• Shorter term responses tend to be in relation to volcanic forcing impacting surface ocean temperatures due to a reduction of solar radiation, but multidecadal changes can be mediated through large-scale ocean dynamic changes in AMOC

• Sea ice expansion coincides with a reduction in AMOC strength due to reduced heat transport to the Arctic allowing sea ice to persist

• Feedbacks can interact with one another in order to amplify and extent their impacts

Halloran et al., 2020

• Deep water formation is the key process driving AMOC, it is started as surface flow in the North Atlantic is driven by the Gulf Stream driving warm salty water north from the equator; as the water travels north it cools, often forming ice and therefore increasing the salinity of the surface water

• Increased salinity increases the density of the water, causing it to sink until it reaches neutral buoyancy, this is the creation of North Atlantic Deep Water (NADW)

• The NADW current flows south to compensate for the north flowing Gulf Stream, the combination of these processes forms AMOC

• The conveyor occurs as NADW is pulled up and warmed via upwelling, this movement of water masses can be considered a linked system or a conveyor belt; the conveyor is considered to have states of ‘off’ and ‘on’ as disturbances in one part of the system can alter processes elsewhere, even causing it to ‘turn off’

Lowe & Walker, 2014

• The Arctic Ocean wave climate is undergoing drastic climate changes due to sea ice retreat due to the increase of swell influence and wave directions changing

• Wave heights are projected to increase up to 6m offshore and 2-3x greater than corresponding 1979-2005 values along coastlines

• These lead to increased wave-driven erosion, inundation and extreme wave events that threaten Arctic coastal communities and existing and emerging infrastructure; this has already been seen in recent years

Casas-Prat & Wang, 2020

• Polar bears use the ice stretching across the ocean surface in the Arctic to access main sources of prey and would be expected to conserve energy in a hibernation-like state in warmer months 

• Anthropogenic climate change is extending the ice free period in the Arctic forcing polar bears to spend more time on land looking for food and not conserving their energy 

• In a studied group in Hudson Bay, they did not hibernate but the food they found also did not meet their calorific needs so the bears lost weight and risk starvation by staying on land 

• The world’s polar bears are endangered by climate change but limiting global warming to the Paris Agreement would help preserve them

France-Presse, 2024

• Combined records show a total glacier mass change of -540 Gt on average from 1819-2019 in Iceland with the equivalent of 1.5 mm of sea level rise

• Almost half the total mass change occurred in 1995-2019 with the most rapid loss from 1994-2010 at around 9.5 Gt per year

• Glaciers in most areas of the world are losing mass due to increasing temperatures associated with global warming, satellite and remote-sensing data shows that these rates are unprecedented

• Although there are substantial temporal and spatial variations, global mass loss trends became clear towards the end of the C20th

• Glaciers in Iceland cover around 10% of the land but many are disappearing, due to the proximity of Iceland to inhabited regions country-wide monitoring has been in place since 1930

Aoalgerisdottir et al., 2020

• The Andes contain a wide variety of topographic and climate conditions resulting in large diversities of ice masses, it contains the largest glacierized area in the SH outside of Antarctica

• The Andean glaciers are placed among the highest contributors to global sea level rise, mitigate against droughts, feed many basins and generate revenue through tourism so their decline is significant 

• They are among the faster shrinking glaciers on Earth with total mass changes from 2000-2018 at around -22.9Gt per year with most negative mass balances in the Patagonian and Tropical Andes

• There is both latitudinal and temporal variabilities in glacier changes responding to climatic events

Dussaillant et al., 2019

• Knowledge of glacier mass balance has expanded since being pioneered around 50 years ago but there is still a problem with short records and biases towards Western Europe and North America as well as wetter conditions

• Glacier mass balance is associated with changes in glacier mass; if accumulation (via snowfall) exceeds ablation (melting and ice carving) the glacier will expand and vise versa

• Changes in glacier mass are accompanied by changes in oceanic mass impacting global sea-levels as well as societies depending on glaciers

• There is no sign of regional trends towards melting that would be expected with warming temperatures, but there is considerable intra-regional variation

• Direct measures have been though stakes and snow pits but it is important to better integrate geodetic and remote sensing methods in the future

Braithwaite, 2002

• High Mountain Asia hosts the largest glacier concentration outside the polar regions and are important contributors to streamflow in one of the most populated areas of the world

• Digital elevation models derived from satellite stereo imagery compute mass balance for 92% of the glacierized area showing total mass change of around -16.3 GT per year from 2000-2016

• There is large intra regional variability with gains of around 1.4 Gt per year in Nyaninqentanghla

• This lower estimate and variability is important for calibrating future models for projecting glacier response to climatic change

Brun et al., 2017

• During 2000 to 2019, glaciers lost a mass of 267 Gt per year equivalent to 21% of observed sea level rise

• There is a mass loss acceleration of 48 Gt per year per decade particularly with glaciers outside of ice sheet peripheries doubling over the last 20 years 

• Glaciers currently lose more mass and at similar to accelerated rates than the Greenland or Antarctic ice sheets separately 

• These estimates can advance understandings of drivers governing distribution of glacier change and be used to design adaptive policy for local and regional scale management of water resources and global-scale mitigation of sea level rise

Hugonnet et al., 2021

• Freshwater scarcity is posed as a global systematic risk

• Two thirds of the global population (4 billion people) live under conditions of severe water scarcity at least one month of the year with nearly half in India and China

• Half a billion people in the world face severe water scarcity all year round 

• Putting caps on water consumption, increasing water-use efficiencies and better shaping of freshwater resources will reduce the threat posed by water scarcity on biodiversity and human welfare

Melonnen & Hoakstra, 2016

• At a regional scale, Greenland ice sheet has experienced accelerating mass loss since 2005 correlated with atmospheric and oceanic warming 

• Mass loss within individual outlet glacier catchments have unexplained variability with mass loss concentrated near the SE and NW

• Glacier thinning is greatest at glacier termini and decreases with distance up-glacier allowing it to be modelled as a kinematic wave, this shows how glacier geology and underlying characteristics impact mass loss

• These variabilities impact predictions of Greenland’s contribution to future sea-level rise

Felikson et al., 2017

• The Antarctic and Greenland Ice Sheets are the last remaining ice sheets since the Last Ice Age 12,000 years ago and store around 68% of Earth’s freshwater

• Between 1992 and 2020, the ice sheets have lost 7.6 trillion tonnes of ice, for Antarctica the West is the most vulnerable due to bedrock being below sea level and Greenland has over 200 major outlet glaciers

• They are influenced through interactions with atmosphere and oceans due to meltwater runoff, warm waters and submarine melting of ice shelves; ice-albedo and brown-pigmented algae feedbacks exacerbate this

• They contribute directly to rising sea levels posing socio-economic implications and risks to people living in low-elevation coastal areas, they also are linked to weakening AMOC and more frequent extreme weather

• They will continue to los mass with greater contributions to global mean sea level, they are vulnerable to positive feedback effects and lose mass rapidly once triggered

Otosaka et al., 2022

• The growth of pigmented algae on ice surfaces increases solar radiation absorption with the effect of contribution an addition 6 Gt of runoff in the SW sector of the GrIS in summer 2017

• In localised patches of high biomass it accelerated melting up to around 26%

• There is a positive feedback loop where higher biomass blooms form in high melt years due to larger areas formed for bloom development and better nutrient availability 

• This is important to estimate Greenland’s sea level contributions in the future an as bare zones and growth seasons for algae will expand in the future

Cook et al., 2020

• GrIS mass loss has recently increased due to enhanced surface melt and runoff critically modulated by surface albedo 

• Greenland’s seasonally fluctuating snowline reduces ice sheet albedo and enhances melt by exposing dark bare ice

• From 2001 to 2017 the process amplified ice sheet melt 5x more than hydrological or biological processes

• In a warmer climate, snowline fluctuations will exert an even greater control on melt due to flatter ice sheet topography at higher elevations

• Snowline elevations are inaccurately predicted forming uncertainties in sea level rise contributions

Ryan et al., 2019

• Limiting warming to 1.5 degrees would halve the land ice contribution to C21st sea level rise relative to current emissions pledges 

• The median decrease is from 25 to 13 centimeters of SLE by 2100 with glaciers responsible for half of the sea level contribution

• Projected Antarctic contribution does not show a clear response to the emissions scenario, but under pessimistic assumptions ice loss could be 5x higher increasing median land ice contribution to 42 cm under current policies and pledges 

• This would severely limit the possibility of mitigating future coastal flooding, adaptation for sea level rise must factor in these uncertainties in Antarctic response especially

Edwards et al., 2021

• Ice sheets and glaciers worldwide have lost mass over the last decades, glaciers worldwide outside of ice sheets have lost mass at an average of 220 Gt per year from 2006-2015

• This impacts slope stability and accelerates sea level rise with ice sheet and glacier contributions as dominant sources 

• This changes abundance, range and establishment of plants and animals as well as habitats and krill distribution in the Antarctic 

• Glacier retreat impacts food and water security due to disrupting agricultural yields, changing water runoff resources and impacting water quality; glacier tourism is also affected

• Global scale glacier mass loss will continue until 2050 with reductions of up to 94 mm under RCP8.5

• This will further decrease stability of slopes, glacier lakes increase as well as floods and river run-off in glacier-fed high mountain basins will change

IPCC, 2019

• Between 2006-2015 the GrIS lost ice mass at an average of around 278 Gt per year and the Antarctic at 155 Gt per year due to rapid thinning and retreat of major outlet glaciers; global mean sea level is increasing as a result

• Mass loss from the Antarctic ice sheet over 2007-2016 tripled compared to 1997-2006 and doubled for Greenland, this is leading to irreversible ice sheet instability

• Ice sheets are projected to lose mass at an increasing rate throughout the C21st, in 2100 the GrIS is projected to contribute 0.15 mm to GMSL rise under RCP8.5 and Antarctic 0.12 mm

• The GrIS is currently contributing more, but Antarctica could become a greater contributor by the end of the C21st due to rapid retreat and instability

IPCC, 2019

• Illustrates the relationship that human activities have a profound contribution to species extinction

• As the human population grows, species extinction advances in a similar trend

Umesh Babu & Nautiyal, 2015

• The financial system underpins our engagement with nature so changing economic models could stop biodiversity loss

• Financial systems act as an extractive force of nature causing ecosystem decline

• There should be an effort to integrate nature and the financial system to stop species extinction

Atkins & Macpherson (eds.), 2022

• Land use is becoming a global issue driven by needs to provide food, water and sheller to the growing population

• Expansion of croplands and pasture associated with expansion of fertiliser and irrigation lead to salinisation, overgrazing, soil erosion and loss of habitats

• The water balance and water cycle is being disrupted causing droughts, a falling water table, oxygen depletion, blooms and waterborne diseases

• Forests are being lost, net radiation is changing to impact climate as well as transmissions of infectious diseases

• We must assess tradeoffs between human welfare and ecosystems to inform policy action

Foley et al., 2005

• As global agriculture and urban areas hit 5 million hectares, habitat sizes decrease by nearly 20% due to the expansion of human activities

Beyer & Manica, 2020

• There is now an argument for the sixth mass extinction event driven by humans with habitat loss being the biggest problem for biodiversity

• Human predation is an issue as well as introduced species becoming predators, disrupting food webs, pollination, outcompeting native species, hybridisation and genetic dilution

• Disease is also a threat and all are exacerbated by globalisation

Whittaker & Fernandez-Palacios, 2007

• Steep declines are seen in wildlife populations with habitat loss driven by the food system as the main threat

• There is little progress in delivery of global agreements or urgency when we must work collaboratively to transform food, energy and financial systems

• Cumulative impacts of biodiversity loss can trigger larger, faster changes that become self-perpetuating when they reach a tipping point

• Food production is causing habitat loss, unsustainable water usage in land and oceans; energy use is also a main driver of climate change and air pollution

• Economic activities are having large impacts

WWF & ZSL, 2024

• The UK is now one of the most nature-depleted countries on Earth with huge threats on land, oceans and in peatlands

• Agriculture is seeing fertiliser use peak along with overfishing and disease becoming bigger threats

• In Wales, vascular plants show consistent declines due to conversion of grasslands and ammonia emissions kill lichens

• In Scotland, warmer summers and more frequent droughts see species become intolerant of new climates, herbicides see vascular plants decline ad sea pressure put pressure on plankton communities

State of Nature, 2023

• A behaviourally mediated trophic cascade in Yellowstone theorised that as wolves were reintroduced the elk would avoid the risky foraging areas and allow the aspen to regenerate

• The data found that the risk of woolf predation alone was unlikely to alter the degree to which the elk limited aspen, the elk population would have to decline in order to allow the aspen to regenerate

Kauffman et al., 2010

• Ecosystems regulate the Earth’s biogeochemical processes and are key to it’s survival, but human impacts are causing declines in biodiversity and subsequent shifts in the assembly and functioning of ecosystems

• Higher levels of biodiversity act as insurance against environmental fluctuation as they act as a buffer

• The effects of losses on productivity are most felt on small-intermediate scales

• The impacts of diversity loss can impact multiple trophic levels

• A larger number of species is required within ecosystems to ensure stability and biogeochemical stability

Loreau et al., 2001

• Consensus that biodiversity loss reduces efficiency of ecosystems, reduces stability, leads to accelerating change, loss of productivity and can be seen across multiple trophic levels to see extinctions more probable

• Multi-functionality of ecosystems is also threatened by biodiversity loss

• Biodiversity has strongly been correlated with provisioning and regulating services such as fishing yields in the past, we must build on what we know to reduce uncertainties and better serve policy and management

Cardinale et al., 2012

• Biodiversity encompasses all living things currently existing on Earth and is useful as it provides food, materials, medicines and support systems to humans

• It can also be seen as an aesthetic thing for enjoyment

• The defining characteristic of the Anthropocene is enormous species loss and habitat degradation caused by human activities

Cox et al., 2016

• Large wild herbivores are crucial to ecosystems but face dramatic population declines as they are threatened by hunting, land use charges and resource deprivation; their loss can have cascading effects so conservation is key in stalling losses

• Large herbivores act as ecosystem engineers, sources of food, facilitators of life for other herbivores, seed dispersers, nutrient cyclers, control the fire regime, allow small animals to exist as well as being important for human food supplies and tourism related jobs and incomes

Ripple et al., 2015

• The effect of decreasing species richness is to decrease the abundance of the focal group leading to less complete depletion of the resources used by that group

• This influences fluxes of energy within ecological processes so can decrease productivity

• Some species exert stronger controls than others, in very diverse ecosystems this is hard to identify

Cardinale et al., 2006

• Ecosystem ecology addresses the interactions between organisms and their environments as an integrated system to realise the true role of species and ecosystem functioning in supporting human welfare

• Globalisation is seeing biological invasions increase to see Earth’s biota homogenising to alter ecosystems

• Human activities can introduce novel chemicals into the environment which shift feedbacks and often the services human communities depend on

• We must manage and protect ecosystem functions to continue to extract human services from them

Chapin et al., 2002

• The advantage of species diversity has long been seen in improving stability of yields

• There are functional characteristics in ecosystems that are particularly important such as nitrogen fixing legumes

• Within ecosystems there is the idea of the trophic cascade which can make the impacts of losses hard to predict

• Biodiversity allows for multi-functionality as well as stability through the buffer concept, portfolio effect or compensatory dynamic effect

Wilby & Hector, 2008

• The loss of apex predators is a cascading problem due to the impact of top-down forcing on global ecosystems

• The new extinction event is characterised by humans and sees the loss of larger bodied apex predators globally

• It is now understood that there is much connectivity within ecosystems and the trophic cascade has been documented in almost all the world’s major biomes

• The loss of apex predators will have impacts on wildfires, disease, physical and chemical natures of the biosphere, soils, water, the atmosphere, species invasion and further biodiversity loss

• The loss of native apex predators can be understood as the ultimate driver of ecological change

Estes et al., 2011

• Food webs have undergone steep regional declines in complexity through loss of links after the expansion of humans in the Late-Pleistocene

• Extinctions have been the main driver of food web complexity loss as well as participatory species

• In areas where food webs are threatened, endangered species loss would decrease links further as they are often key to food web preservation

• It is possible to recover food web complexity through natural recolonisation and reintroduction of historic ranges

Fricke et al., 2022

• There is evidence humans began playing a role in extinctions in the Late-Pleistocene around 10,000-50,000 yeas ago

• In this time hominins first appeared in Africa but had very little impact on large herbivores

• Expanding grasslands, declining CO2, fires, pathogens and competing species seem to have played major roles in African megafaunal decline; the role of humans is unclear

Bobe & Carvalho, 2018

• Plant and fungal research is key to achieving many of the SDGs

• Documenting and describing them is key in protecting these species, they can also be seen as possible sources of food and medicine as well as possible losses being projected into the future

• We can alter traits of plants to improve efficiency and identify overlooked sources of food, energy and healthcare

• There are efforts to decolonising similar research and encourage more collaboration and equitable implementation of policy

Antonelli et al., 2020

• The 30×30 target is key to ensuring survival of the planet against biodiversity loss

• The right areas must be chosen and this should come from understanding the importance of all species

• Monitoring should be focused and to core standards as well as all stakeholders being involved to see collaboration fight biodiversity loss

Antonelli, 2023

• Identifying priority areas for biodiversity is key for directing conservation resources, there is a need to reassess global allocation of these resources as knowledge on global patterns of biodiversity improves

• Species richness is globally uneven in all species including those with small range sizes, there are broad similarities but the most effective efforts would focus on specific land parcels

• Birds and mammals are generally concentrated in moist tropical forests with small ranged species being more specific 

• Areas of priority for conservation do not overlap, the most effective conservation would rely on small ranged species centres of diversity as they are very concentrated and many are endemic so face large risks of extinction

Jenkins et al., 2013

• The tropics contain many more species of plants and animals than higher latitudes, this may be due to the diet of animals

• For plants, they need sunlight so the energy hypothesis shows that species richness is correlated by to how much energy is captured by the vegetation; this is in terms of sunlight and evapotranspiration

• For animals higher productivity and greater structural complexity resulting from higher biomass is key as this supports many smaller species

• Aphids provide an anomaly to the latitudinal biodiversity gradients and some argue this is simply due to the tropics having a higher land area

Cox et al., 2016

• Hotspots must be protected as they have endangered habitats that are home to numerous endemic species; there are 25 hotpots covering 2% of Earth’s surface but representing 50% of terrestrial species diversity 

• The Tropical Andes Hotspot has the most diverse vascular plants, the Mesoamerica Hotspot the greatest diversity of amphibians, the most important island hotspot is Cuba and the California Floristic Province Hotspot is one of the few located within the borders of a developed country

• Across all sites, the Caribbean, Philippines and Madagascar are considered priority hotspots due to high levels of endemism but have lost many natural forests in recent years

• The majority of hotspots are located in countries where poverty is rampant and human density is expanding complication efforts to preserve habitats

Mittermeier et al., 2002

• The species-area relationship states that larger areas tend to support more species due to having greater habitat diversity and lower extinction rates

• More isolated areas tend to have lower species richness due to lower immigration rates to the island

Whittaker & Fernandez-Palacios, 2007

• Communities are distributed due to dispersal constraints, environmental constraints and internal dynamics and the results are measured in terms of species richness

• Gradient analysis, classification and ordination can be useful in understand species patterns in spaces but boundaries are not always clear

• Community patterns also occur in time if a species is capable of reaching a location, appropriate conditions exist there and predators do not preclude it; these community changes follow disturbances and can be primary or secondary succession

• Succession can be explained by competition-colonisation trade-off, successional niche mechanisms, facilitation, interactions with enemies, resource-ratio hypothesis, vital attributes, the role of animals and will eventually result in a polyclimax

• Patch dynamics also see a landscape as made up of patches of communities, this is formed by disturbance and migration between patches

Begon et al., 2006

• Passive rewildings refers to spontaneous development of ecosystems without direct intervention such that abandoned land restoration occurs via natural succession

• This has advantages in preserving native plant genotypes, avoiding pests and diseases on imported saplings, better resilience to drought and reduced management costs but will see some species out competed and habitats lost

• Evidence from monitoring passive rewilding in New Wilderness and Old Wilderness in England see that New Wilderness gained 86% vegetation cover after 23 years and Old Wilderness 100% cover averaging 13.1 metres tall after 53 years

• The species compositions different from ancient woodlands and tree colonisation was spatially clustered due to wind-dispersed seeds and clusters of oak resulting from hoarding of birds and animals

• This provides long term reference data to inform predictions of further passive rewilding in temperature Europe as closed-canopy woodlands can readily establish due to natural succession

Broughton et al., 2021

• Ecological release occurs when a species colonising an island encounters a biotic environment in which competition is absent so their niche expands

• This may mean a larger realised niche without changes to the fundamental niche, but can also be character release where an increased variance of genetically coded features such as beak morphology occurs e.g. finch species in Hawaii

• Changes in niche breath can b accompanied by a loss of defensive traits, this may contribute to the demise of an island species as it lacks fear and cannot flee from humans or predators 

• Ecological release may lead to adaptive radiation where the species evolves into multiple new species 

• Density compensation also occurs when a lower area-adjusted species richness raises increased population sizes per area linked to the expansion of niche spaces leading to density overcompensation

Whittaker & Fernandez-Palacios, 2007

• Invasive rats are one of the world’s most successful animal groups causing native species extinctions and ecosystem change particularly on islands

• They have now been introduced by humans to over 80% of the planet’s islands and impact the environments through opportunistic foraging and preying on plants, birds, reptiles and invertebrates

• Rate eradication is often impossible but population control is routinely carried out on many islands as a management tool

• There is a need to expand rat control distribution especially in biodiversity hotspots, improvement of methods is needed as well as regular monitoring to assess short and long term effectiveness

Duron et al., 2017

• Darwin’s travels on HMS Beagle taught him that islands are an important source of evidence for evolution as they are young and have relatively few species, evolutionary adaptation and species proliferation are obvious and easy to study

• They are also isolated allowing evolution to take its own course free of influence resulting in unusual faunas and floras unlike those found anywhere else

• Island research provides valuable insight into speciation and adaptive radiation

Losos & Ricklefs, 2009

• Gendered differences and inequalities mean that women, girls, people living in poverty, rural communities, sexual and gender minorities and Indigenous Peoples are differentially and disproportionately affected by biodiversity loss

• This impacts human rights, health, food, water and sanitation, culture and self-determination

• Often women face higher domestic burdens, loss of income, declining health, exposure to gender-based violence, loss of culture and impacts on wellbeing; girls see reduced access to education

• The negative impacts are often interconnected and perpetuate one another 

• Women’s voices are often not heard or represented in biodiversity policy, there must be better representation of their rights, knowledge and access to benefits in the future

Booker et al., 2022

• A keystone species is one whose effect is large and disproportionately large relative to its abundance, here less abundant species have strong effects on communities and ecosystems 

• Top predators tend to be assumed to be the most important due to having high per capita effects and low collective biomass, but keystone species can also be found at lower trophic levels

• An example of lower trophic level species is soil bacterias or lichens that fix nitrogen and support snails

• The keystone concept is important to identifying the most suitable areas for biodiversity preservation, it may be useful to maintain keystones instead of focusing on endangered local species or hotpots to maintain maximum ecosystem functioning

Power et al., 1996

• The keystone plant resources concept describes certain plant species in tropical forests vital to community stability and diversity dye to providing food resources to vertebrate consumers during a season of scarcity 

• In a lowland western Amazonian rainforest, it was found only less than 5% of plant communities consistently provided fruit for a broad set of consumers during a period of resource scarcity making them keystone plant resources 

• This has implications for conservation and management of Amazonian forests

Diaz-Martin et al., 2014

• Extensive tree planting is widely promoted in Africa with the AFR100 targeting 100 million hectares of land for restoration, however this is based on erroneous assumptions that grassy biomes are deforested and degraded

• NETs may not actually be effective as there could be negative climate effects such as changed in albedo

• There needs to be a huge amount of money and work over a large scale for this to be effective

• Grassy biomes are often better at conserving forest and water resources than plantations, these schemes may distract from the real need to decrease fossil fuel reliance

Bond et al., 2019

• Better stewardship of land is needed to achieve the Paris Agreement, the use of NCS can provide around 37% of cost effective CO2 mitigation needed by 2030

• Around half of the maximum NCS potential is cost effective, but this should not delay action on reducing fossil fuel emissions

• Specifically important pathways are forest, reforestation, avoided forest conversion, improved forest management, agriculture and wetlands

• These do face challenges such as uncertainties, barriers to implementation, climate change feedbacks and unfocused policy

Griscom et al., 2017

• NBS works with and enhances nature to mitigate or adapt to climate change while simultaneously providing benefits to biodiversity and people; it has a huge range of co benefits

• We live in a time of environmental challenge but also opportunity, specifically the post-EU window allows for new policy to be developed that focuses on the importance of NBS

• NBS can stimulate green employment and boost human health and wellbeing but better assessment frameworks and evidence will be needed to ensure this

• Key NBS comes from peatlands, woodlands, salt marshes, arable landscapes and urban street trees

Stafford et al. (eds.), 2021

• The UK has one of the lowest levels of woodland cover of any European country, the England Tree Strategy hopes to expand trees and woods to tackle nature and climate crises

• Well located tree cover has the potential to reduce risks of flooding, filter pollutants, create jobs, provide sustainable timber and improve human health

• The scale of return on investment will require trees to be planted in the right places to maximise co-benefits

Mann, 2020

• Flood risk and associated impacts are major concerns following widespread flooding in the UK in December 2015, this saw attention turned from hard engineering solutions to soft engineering

• Tree cover could increase the storage capacity of catchments, increase lag time, reduce water discharge and reduce flood risk particularly in smaller catchments

• There is little direct evidence for this as well as unpredictability of the weather and potential for adverse effects justifying weak flood protection policy and action

Carrick et al., 2018

• Storms are no longer isolated events due to climatic change with relentless rainfall devastating lives and properties

• Climate change increases the likelihood of extreme rainfall to see flooding become a significant risk to the UK

• Trees can aid in reducing food risks due to canopy cover, roots, urban trees and deadwood and dams but we need more

Woodland Trust, 2024

• Climate change will alter long term provisions of goods and services people obtain from the land due to temperature rises, heavy rainfall and reduced water availability in summer

• Current policies and low-regret adaptation actions may not be sufficient, more transformative actions are needed accompanied by awareness and meaningful long-term planning 

• There will be short-term costs but also long term benefits, anticipatory land use changes are the most cost effective

Committee on Climate Change, 2018

• As urban populations grow and cities magnify the impacts of climate change, mitigating and adapting to climate change in urban areas becomes increasingly important 

• NBS are more flexible, multi-functional and adaptable than traditional approaches

• Cities face challenges such as sea-level rise, coastal storms, extreme heat, water security, inland storms and pluvial flooding that are exacerbated by the urban heat island effect and highly impervious surfaces

• NBS can aid in adapting to these issues, but more research is needed into its effectiveness, costs and benefits and equity in terms of distribution of these solutions

Hobbie & Grimm, 2020

• Forests must play a part in removing vast amounts of CO2 from the atmosphere, they could store enough carbon to limit global warming to 1.5 degrees but this would require adding up to 24 million hectares of forest every year until 2030

• The regeneration of natural forests must be prioritised and this must have tighter definitions, transparent reporting and outcomes that state tradeoffs

• The most effective place to plant trees is in the tropics and subtropics and this must be natural regeneration through protecting the land from disturbances to allow trees to return and flourish as well as being protected

• Plantations and agroforestry are not as effective due to planting of monocultures and too smaller scales

• Bioenergy with CCS can also be used alongside natural forests in order to limit warming to 1.5 degrees

Lewis et al., 2019

• Biodiversity increases ecosystem resilience for a broad range of climatic events including wet or dry, moderate or extreme and brief or prolonged 

• Productivity of low-density communities changed by 50% during climatic events by high diversity communities changed by only 25%

• Recovery was not impacted by biodiversity levels showing it stabilises productivity 

• Anthropogenic environmental changes driving biodiversity loss are likely to decrease ecosystem stability; conversely, restoration could restore it

Forest et al., 2015

• High levels of biodiversity acts as insurance against environmental fluctuation acting as a buffer and stabilising influence

• There is a minimum number of species essential for ecosystem functioning and a larger number is needed to maintain stability in changing environments in order to ensure biogeochemical stability

• Biodiversity also allows for multi-functionality of ecosystems

Loreau et al., 2001

• Restoration and rehabilitation projects are key to recovering services, goods and resources ecosystems offer to humankind

• Man-made solutions are high-maintenance, costly and ineffective over longer time periods as they depend on external inputs of energy, money, management and control 

• NBS are more sustainable and superior in land management as they use natural flows of matter and energy, take advantage of local solutions and follow seasonal and temporal changes as well as having co-benefits to the sustainable economy and society of a region

• Soil-vegetation solutions enhance soil health and functions whilst landscape solutions focus on connectivity 

• By reducing connectivity of the landscape less rainfall can be transformed into runoff and flood risk, droughts and erosion problems are reduced

Keesstra et al., 2018