Impacts of climate change are global and dynamic

Impacts on ecosystems

• biotic and abiotic components interact with each other and form an ecosystem

• because all the elements within an ecosystem are interrelate, these systems are highly complex

• all ecosystems must maintain a delicate balance between all of their members in order to thrive

• human interference and extreme natural events can tip this balance and threaten an ecosystems health

Marine ecosystems

• 50% of all photosynthesis on Earth happens in oceans by phytoplankton

• ice algae decimated by shrinking sea ice in the poles - base of marine food chain

• reduction in polar bear pop. - projected 2/3 decline by mid-century

• coral reefs threatened by bleaching - 80% of reefs already lost in the Caribbean

• walrus/seals affected by loss of sea ice - used as diving platforms or resting on to give birth

• warming seas limit food supplies for fish species - some species indigenous to UK have moved poleward e.g. haddock and cod

Coral reefs under threat

• Great barrier reef - 500,000 years old

• almost 25% of the GBR died in 2016

• 50 million years of symbiosis with their algae

• they protect coastlines from storms and erosion

• provide jobs for locals

• 5 mass coral bleaching events over 9 years due to CC

• temps around coral reefs were the warmest they have been for the past 40 years

terrestrial ecosystems

• habitat change in tundra due to melting permafrost

• tree line will advance north into what was tundra

• Scotland could lose 90% of its arctic-alpine habitat as some species would need to migrate northwards

• spring occurring earlier creates loss of synchronisation between species - animals awake from the hibernation earlier or breed before the emergence of food resources

Impact of rising temperatures on the AT ecosystem and on people

• the arctic tundra has experienced habitat changes - loss of 18% since 2000 due to permafrost thawing, wetlands expanding and forests expanding northwards

• more wild fowl and waders migrating due to warmer temp.

• spring arrives earlier 2.3-5.2 days earlier over last 30 years

• breeding season is longer - more abundant insect pop. (food for birdlife)

• taiga expansion further north may help to mitigate CC (negative feedback)

• loss of sea ice might mean coastal tundra in Russia, USA and Canada can be developed for economic gain

Impact of rising temperatures on coastal mangroves in Bangladesh

• Sundarbans are the largest mangrove forest in the world - 10,000km2 - specially adapted plants/trees that can survive in brackish water - one of the richest ecosystems in the world

• SL rise, and reduction in sediment input from rivers, is already leading to retreat of 40m per year in some parts

• home to endemic species e.g. Bengal tigers and River dolphins

• increasing intensity of cyclones and SLR increases the salinity which threatens the health of entire ecosystem

• loss of Sundarbans would reduce protection from storm surges and threaten the 7 million people who rely directly on the ecosystem

Impact of ecosystem decline on human health - health and disease

• plants are essential for medicines - 25% of drugs used in modern medicine are derived from rainforests

• due to ecosystem decline - animals live closer to with one another and with humans, creating ideal conditions for the spread of zoonotic diseases e.g. COVID-19

• the poor and elderly are usually more vulnerable to disease

Impact of ecosystem decline on humans - global economy

• according to World Economic Forums, more than half of the worlds GDP ($44 trillion) is highly or moderately dependent on nature - many businesses are at risk due to increasing nature loss

• some sectors of the global economy and places will be more vulnerable than others e.g. tourism locations reliant on ecosystem services e.g. Caribbean suffering coral reef decline

Impact of ecosystem decline on humans - livelihood decline

• humans derive $125 trillion of value from natural ecosystems per year through employment

• globally, 3 out of 5 are dependent on water

• however, some are more vulnerable than others; the agricultural sector employs over 60% of the world’s working poor and in global south, forests are the source of livelihoods for over 1.6 billion people

Impact of ecosystem decline on humans - protection from natural hazards

• biodiversity makes the earth habitable and provide nature-based solutions that buffer us from natural disasters e.g. floods and storms

• e.g. the clearance of over 35% of the world’s mangroves for activities has increasingly put people living in coastal locations at risk from floods and SLR

• some are more vulnerable than others - mangroves are located in tropical areas e.g. Bangladesh, already suffering from SLR

Redistribution of Earth’s species looking to the future

• marine, freshwater, and terrestrial species alike, the first response to changing climate is often a shift in location, to stay within preferred environmental conditions

• because different species respond at different rates and to varying degrees, key interactions among species are often disrupted, and new interactions develop

• these idiosyncrasies can result in novel biotic communities and rapid changes in ecosystem functioning, with pervasive consequences that affect both biological and human communities

• on land, species are moving to cooler, higher elevations and in the oceans they are moving to colder water at greater depths

• even if GHG emissions stopped today, the responses required in human system to adapt to the most serious effects of climate-driven species redistribution would be vast

Health issues associated with CC

• spread of vector borne diseases e.g. malaria, dengue fever from higher precipitation and flooding

• heat stress can increase the risk of cardiovascular, respiratory and renal diseases

• malnutrition especially in areas prone to drought and floods

• mental health problems associated with anxiety - can ultimately lead to suicide

• release of bacteria and viruses from melting permafrost

Will all people be affected to the same extent

• certain groups have higher vulnerability to climate-sensitive health impact owing to - their age, gender, social marginalization, other health conditions like HIV

• LIDCs and even EDCs will be more vulnerable due to lower economic dev. and social-economic status of the pop.

  • less money to put towards adaptation techniques therefore suffer more from direct impacts of CC on health

  • cost of CC means less money to put towards healthcare systems

  • cost of CC means less money to put towards healthcare systems

  • BUT, higher LE in ACs means that healthcare services could be very stretched here due to spending on the more vulnerable e.g. on the elderly suffering heat stress

• Overall, socioeconomic costs of health problems caused by CC are considerable now and will get worse in the future without effective mitigation and adaptation strategies

Climate change and malaria

• Anopheles mosquitoes thrive in regions with warm temp., humid conditions, and high rainfall

• warm temps are also required for malaria parasites to complete their growth cycle within the mosquitoes

• temps must be between 15-60C with high rainfall and humidity 60% and over

• malaria may expand into new regions e.g. the Mediterranean, higher altitude areas, but some areas will have less malaria e.g. Botswana predicted to have less rainfall

• there is still uncertainty about future transmission as there are multiple other factors affecting spread of disease e.g. socioeconomic development, drug resistance, and immunity

Bangladesh - on the road to malaria elimination

• there has been historic reduction of malaria over 93% in Bangladesh from 2008-2020

• of the malaria remains, 90% occurs in 3 districts

• sharp decline in deaths from malaria due to implementation - rapid diagnosis and treatment, use of insecticide treated nets, use of indoor residual spray, focus on the most vulnerable

AO2 malaria - the power of solutions

• 10 years ago, 45% of all hospital admissions in Africa were caused by malaria

• now, it is dealing with malaria much better due to mitigation efforts - 3.3 million lives have been saved due to international malaria control interventions

• malaria mortality rates in children have fallen by 54%

• USAID have declared that the war on Malaria is ‘the greatest success story in global health’

Mental health crisis arising from climate change

• scientists depict a vicious circle where climate impacts increase mental health difficulties, leaving people even more vulnerable to consequences

• but tackling CC could turn this into a virtuous circle because action by players not only cuts impacts of heating but also boosts peoples mental wellbeing, giving them hope and healthier lives

• 2005 - Hurricane Katrina devastated parts of Louisiana and Mississippi, displacing over 1 million people and causing over 1800 deaths

• the disaster had long term mental health consequences, with thousands of survivors experiencing PTSD, depression and anxiety

• studies found over 30% of Katrina survivors reported severe mental health struggles, many losing jobs, homes + loved ones

CC impact on health via food supplies - indirect effect of CC

• higher temps = increased food contamination

• higher rainfall = greater risk of flooding + contaminated water = increased risk of diarrhoea in LICs and ACs

• droughts/floods - reduces crop yield/food production = threatens food security and increases malnutrition/undernutrition

• CC is a LT threat to food security - by 2050, risk of malnutrition could rise by 20%

• Southern Madagascar experienced its worse drought in 40 yrs, leading to prolonged food and water shortages (2021-2022)

  • this caused failed harvests and widespread malnutrition, affecting over 1 mill people

  • UN described the situation as one of the world’s first CC-induced famines, thousands forced to migrate

Is CC solely responsible for rise in some diseases

• there is an increase in many infectious diseases, including some newly-circulating ones e.g. HIV/AIDS, SARS

• this reflects the combined impacts of rapid demographic, environmental, social, technological and other changes in our ways of living

• CC is just one variable in this - health problems are also exacerbated by other factors and changes e.g. diet, encroachment of nature (zoonotic diseases)

Case study - Cyclone Amphan 2020

• a category 5 storm, struck Bangladesh in May 2020 causing catastrophic damage

• over 2.4 million deaths were damaged or destroyed in India and Bangladesh

• 128+ deaths (mostly due to flooding, electrocution, and collapsed buildings)

• contaminated drinking water increasing risk of diseases

• saltwater intrusion from storm surges damaged vast areas of farmland, affecting rice and fish farming

• heavy rainfall and storm surges led to severe river flooding and soil erosion

• Bangladesh have spent a lot of money adapting, the low death toll shows success of their adaptation

Case study - Pakistan floods 2022

• unprecedented monsoon rains - 3X usual amount of rainfall) caused catastrophic flooding across Pakistan, submerging 1/3rd of the country

• at times, 17,000 cumecs of water were flowing in the Indus River, 3X its usual discharge, with a 100 km long lake forming in the Sindh Province

• 1,700 people died, and more than 33 million people were displaced

• floods destroyed 2 million homes (particularly vulnerable were mud brick homes), millions of acres of farmland and critical infrastructure (150 bridges), leaving lasting econ. and humanitarian impacts

Cased study - European heatwave 2022

• the UK recorded its highest-ever temp. of 40.3C in July 2022

• led to 61,000 excess deaths across Europe, particularly among the elderly

• hospitals were overwhelmed with cases of heatstroke, dehydration and cardiovascular stress

• Spain and Portugal suffered vast wildfires, burning thousands of hectares of land

• transport system failed, with train tracks buckling and roads melting under extreme heat

• energy demand surged, straining power grids and causing blackouts in some areas

• agricultural losses were severe, with crops e.g. wheat, suffering heat stress, reducing yields

Risk from extreme weather is exacerbated by CC

• implications of extreme weather for people and environment vary from place to place

• depends on type of extreme weather (some are worse than others), its magnitude (severity, scale and frequency), relative vulnerability of the people and environment that might be affected

Which extreme weather event poses the greatest risk?

Drought:

• more widespread, agricultural impact, temporally long-lasting, food and water source impacted, hard to adapt

• 40% of the land surface, containing 70% of pop. and worth 70% of agricultural production is exposed to drought

Flood:

• can use flood management

• occurs in over 1/3rd of the worlds land areas, affecting 82% of the worlds pop.

• 10% of land surface is very prone to floods, containing 40% of the worlds pop.

Storms:

• inequality between ACs and LIDCs in terms of how effective their responses are

• conc. in tropical coastal areas, covering 6.7% of land area but 24% of worlds pop.

• areas often developed and contain much infrastructure + GDP

Disaster response curve

• impacts of extreme weather event and recovery vary sig. across the development spectrum

• Park’s model shows the impact of extreme weather on QOL over time

• Curve A - shows small impact of QOL and short response phase, life returns to normal within a few months - usually ACs

• Curve B - QOL more impacted than A + reconstruction takes longer, but mitigation improves QOL, meaning the community is better prepared for next extreme weather event e.g. Bangladesh adopted rigorous mitigation + management following 300,000 deaths from Cyclone Bhola in 1970

• Curve C - shows major impact on QOL, slow reconstruction phase, even years later, QOL has not returned to levels before the disaster → e.g. Pakistan 2022 floods

Vulnerability is affected by location and adaptive capacity

• depends on 2 main factors - location, their ability to cope

• vulnerability is often linked to poverty this means that many of the most vulnerable areas are in the developing world

• e.g. subsistence farmers are directly reliant on the climate for the successful cultivation of their crops and raising livestock e.g. Nomadic Pastoralists in the Horn of Africa

• GDP in Bangladesh - $2,700, main source of income is agriculture, high pop. density

Location driving vulnerability

Latitude + climate zone:

• different climate zones experience different types of climate hazards

• tropical regions are more exposed to heatwaves, cyclones and heavy rainfall e.g. Bangladesh, arid regions face droughts and desertification e.g. Horn of Africa, polar regions → rapid warming leads to ice melt

Proximity to oceans and coastal areas:

• coastal areas more exposed to rising SL, storm surges + hurricanes, e.g. Bangladesh → 80% of the country is flood prone; storm surges and river flooding threaten millions

• small island nations face threats due to SLR = Maldives+ Tuvalu → SLR could submerge entire nations by 2100

Elevation and terrain:

• low lying regions more vulnerable to flooding e.g. The Netherlands

• Mountainous regions facing glacial melt, landslides → Himalayan countries e.g. Pakistan, risk of glacial melt surges in spring

River systems and floodplains:

• river deltas and floodplains highly fertile but prone to seasonal flooding - Ganges-Brahmaputra delta prone to annual monsoon flooding

• more extreme rainfall increase risk of floods → Yangtze River, extreme rainfall in 2020 causing record breaking floods

Government capacity and climate policies

ACs:

• strong governments that enforce climate adaptation policies e.g. flood zoning, emissions reduction

• can allocate funds for research, renewable energy and sustainable infrastructure

• have disaster response teams and efficient emergency management

LIDC’s:

• weak governance, making it difficult to implement climate adaptation strategies

• corruption and lack of funding prevent investment in long term solution

• emergency response is slow and inefficient, leading to higher death tolls

Economic dependence on climate-sensitive sectors

ACs:

• have diverse economy, so a disaster in one sector does not collapse the whole economy

• can shift to climate-resilient industries e.g. renewable energy, tech. finance

• provide insurance and financial aid to businesses affected by climate disasters

LIDCs:

• rely heavily on agriculture, fishing and natural resources which are vulnerable to droughts, floods and storms

• limited financial resources mean farmers cannot afford crop insurance or adaptation measures

• when crops fail, millions face food insecurity and econ. collapse

Social inequality and vulnerable communities

ACs:

• have social safety nets e.g. disaster and relief funds, insurance and social services to help affected people

• stronger public health systems help prevent disease outbreaks from CC

• however, social inequality within ACs bring vulnerability

LIDCs:

• higher levels of poverty mean people cannot afford to evacuate or rebuild after disaster

• women, children, and marginalised group are disproportionately affected by extreme weather and health impacts for CC

• many people live in slums or informal housing, which cannot withstand extreme weather and diseases e.g. malaria

The horn of Africa Drought (2020-2023)

• Ethiopia, Somalia, and Kenya experienced their worst drought in 40 years, driven by consecutive failed rainy seasons

• 20 mill. people faced severe food and water shortage

• livestock deaths exceeded 9 mill., devastating livelihoods in pastoral communities

• the crisis was worsened by CC, which has disrupted traditional rainfall patterns

Adaptive capacity in Bangladesh

• it is vulnerable due to being in a low lying coastal region, low GDP, high % of people in primary sector etc.

• however, the low death toll after Cyclone Amphan can be explained to Bangladesh’s long term effort to reduce vulnerabilities

• e.g. in 1970 it had 42 cyclone shelters, now it has 12,000 that serving 5 mill. people

• a system of warning messages informing people about evacuation ranging from social media to people on bicycles with megaphones

• training in school so announcements are trusted and pop. knows how to react and why

• these efforts are appropriate and low cost so less vulnerable

• econ. development can be a major obstacle to successful mitigation but even with a low GDP the gov. has focused on CC adaptation, enhancing resilience and reducing vulnerability

Vulnerability in Australia - Tennants creek, Northern territory

• tennants creek scores a max. of 10 on the Social vulnerability index to CC partly due to social deprivation associated with indigenous people 55% of pop. = aboriginal

• number of days with temp above 40C is expected to increase from 22 to 48 within the next decade

• extreme rain events are projected to become more intense

• avg. family income is only 67% of avg. family income for Australia

• minority ethnic pop. with low incomes and poor access to education and health services

• local scale impact but there is variation in vulnerability

Growth in renewable energy - econ. opportunities

• countries have set ambitious targets for wind, solar and hydropower

• Saudi Arabia, home to one of the world’s biggest oil reserves is looking to generate the bulk of its electricity from renewables and nuclear power by 2040

• A company in Panama is building Central America’s biggest wind farm (215 MW Penonome plant) would prevent the release of 400,000 tonnes of CO2/year

Green construction and architecture - econ. opportunities

• by 2050, more than 6 bill. people will live in urban areas

• cities such as Freiburg in Germany are becoming blueprints for urban dev.

• 40% of the city is forested

• wastewater system allows rainwater to be harvested, reused or seep back into the ground

• strict energy policy based on saving, efficient tech. and renewable energy sources including a solar business park

• 400km of cycle paths

• green cities are achievable in many locations

Opportunities - Arctic

• CC in Arctic is re-shaping global econ. by opening shorter trade routes and extending shipping lanes through melting ice

• swifter deliveries between EU, US and Asia with 3% lower carbon emissions and distances cut 45% compared to the Suez and Panama canals

• however, there is potential for conflict due to geopolitical tensions over ownership of trade routes, the players include Russia, USA, Scandinavia, and China

Opportunities in Bangladesh

• Bangladesh has invested more than $10 billion in CC actions

  • strengthening river embankments

  • building emergency cyclone shelters

  • adapting rural households farming systems

  • reducing saline water intrusion

  • implementing early warning systems

• However, despite the considerable progress that the Gov. and Bangladeshi people have made, they face continuous challenges associated with CC being a being a hazard hotspot

Opportunities in the Netherlands

• in Rotterdam, urban planners have created ‘Water Plaza’ to help minimise risks from river flooding and this created sociable spaces for the communities there

• inequality has been addressed partially - a greenhouse nearby run by an immigrant Turkish community - the value of houses in the neighbourhood have gone up

• 3 pools have been installed that fill up when it rains, used for recreational pursuits, they can be used as recreational spaces when they are dry

• they are surrounded by trees, garden plots with tall grasses, flowers and continuous concrete benches