How and why has the era of industrialisation affected global climate?

Evidence for CC - Increases in temp

• 2023 warmest year for mean land and ocean temps since records began in 1880

• 2023 was the 45th consecutive year of an increase in annual global temps rise

• temps have increased by 1.5 since 1900 - 2/3rd of this warming has happened since 1970s - impact depends on public acceptance

• the IPCC said the temp rise must be limited to 1.5 degrees by 2100

• spatially and temporally sig. - felt all over the world and seasonal temps can be compared to previous years

Evidence for CC - shrinking valley glaciers

• between 1961-2005, the thickness of small glaciers worldwide fell by 12 metres

• it is predicted in the Alps, valley glaciers may shrink by 90% by the end of the century

• in 1850, 150 glaciers existed in Glacier National Park, Montanta - today it is only 25 glaciers

• The rate of glacier decrease is increasing

Evidence for CC - rising sea levels

• since 1900 the average rise was 1-2.5mm/year, now it is 3.4mm/year

• this is caused by the other factors mentioned such as temperature rise and glacier shrinkage

Evidence for CC - Decreasing sea ice

• in the winter Arctic sea ice covers 17 million km2 shrinking to 4 million km2 in the summer

• 2012 - Arctic sea ice shrank to a new min of 3.63 million km2

• since 1979, Arctic sea ice has declined both in extent and thickness - 12.6% per decade

• no clear long term trend in Antarctica

Evidence for CC - Decreasing snow cover

• spring snow cover has declined by 2% per decade since 1966 in the N hemisphere

• Albedo of snow = 85-90% therefore positive feedback occurs and there is more absorption of heat

Evidence for CC - Increasing water vapour

• Water vapour in the atmosphere has been increasing at 1.5% per decade over the past 30 years due to evaporation rates being enhanced

• water vapour is predicted to double by 2100

• it is the most abundant GHG but stays in the atmosphere for a much shorter period of time compared to other GHG’s

• can cause positive (increase evap.) or negative (cloud cover) feedback cycles

• spatially sig. - flooding, hurricanes

A02 for evidence for CC

• Climate has change throughout history - just in the past 650,000 years there has been 7 cycles of glacial advance and retreat - e.g. abrupt end of the Devensian 11,700 years ago

• BUT - current warming trend is especially sig. because most of it is likely because of human activity and it proceeding at a rate that is unprecedented over decades to millennia

• Technological advances enabled scientists to collect many different types of information about the climate on a global scale - this is collected over many years, revealing the signals of CC

• ice cores from Antarctica show the Earth’s climate responds to changes in GHG levels - shows that current warming is 10 times faster than the avg. rate of ice-age-recovery warming

• ‘Scientific evidence for warming of the climate system is unequivocal’ - IPCC 2017

• interpretation of this evidence must be combined with other evidence - it provides interdisciplinary validation from multiple different fields

• many aspects of CC are visible and measurable - extreme weather events link the abstract concept of CC to real life events

More information on GHG

• not only the level of C02 in the atm. that matters but the rate that this has changed, historical changes in C02 conc. tended to occur over centuries but mankind has managed to achieve even larger changes in a matter of decades

• this gives species, planetary systems and ecosystem much less time to adapt

• humans have increased atmospheric C02 conc. by more than 1/3rd since the industrial revolution - (c02 accounts for more than 75% of all anthropogenic GHG emissions)

Increased emissions of GHG’s

1. energy demand - due to industrialisation and technological advances particularly in manufacturing + transport (now fossil fuels supply 87% of the world’s energy releasing 10 billion tonnes of c02/year) + coal emits 50% more C02 than natural gas and China + India’s economies are still largely powered by coal

2. population growth and affluence - (from 1 billion in 1800 to 7.8 billion in 2020), inc. pop = inc. energy consumption for heating, electricity transportation etc. , more food required = agricultural activities expanding so inc. deforestation, livestock emitting methane

3. land use change - accounts for 1/3 of GHG emissions, loss of carbon sinks due to deforestation of forest, 40% of global land surface used for agriculture, 5.2 million trees cleared from 2000-2010, carbon-rich peatlands drained+degraded for agriculture

Balance of anthropogenic emissions changing

• China has become the world’s largest emitter early in the 21st century due to its reliance on coal

• since 1960’s sig. regional shifts have occurred in the emissions of GHG - Asia’s increasing sig. whilst NA, Eu have stabilised, UK has declined

• global emissions highly uneven - the top 10 emitting countries account for 80% of all emissions

• But when c02 emissions are measured in capita, ACs e.g. Australia, Germany + UK much ahead of EDC’s (e.g. USA emits 14.3 tonnes/year/person of C02, compared to 8.4 in China

• but until 1882 more than 50% of the world’s cumulative emissions came from the UK

• much of the emissions from manufacturing in China are linked to exports consumed by AC’s therefore it reflects a global economic dynamic

How have humans enhanced GHG effect

• GHG layer has become thicker given that C02 conc. have inc. from 280ppm in 1800 to over 420ppm today

• therefore there are more GHG particles to intercept, absorb and re-emit LWR thus raising global temps of surface + atm.

• less LWR lost to space

global mean energy balance

• energy balance refers to the balance between the amount of incoming SWR and outgoing LWR

• Radiative equilibrium → incoming radiation 240 watts/m2 = outgoing radiation of 240 watts/m2

How are humans influencing the global mean energy balance

1. inc. volume of GHG in the atm. causing more LWR to be trapped so less LWR is lost to space

2. warming of earth’s atm., surface and ocean is altering the earth’s reflective surfaces so less snow + ice coverage means less reflection of SWR and more conversion into LWR

• together, these influences result in radiative disequilibrium because incoming radiation is greater than outgoing radiation

UK timeline - Industrialisation + peak emissions and decline in coal use

1. industrialisation, economic growth and urbanisation:

   • UK’s primary energy source for over a century was coal in the industrial revolution which powered factories, transport and homes

   • Industrial growth demanded large-scale combustion of fossil fuels

   • urbanisation and population growth catalysed energy demand

   • as late as 1961 output was still more than 120 million tonnes

2. Peak emissions and decline in Coal use:

   • abrupt decline in emissions when GDP + economic activity fell e.g. during the 1921 miners strike and general strike of 1926

   • decline in 1980s associated with economic recession and widespread unemployment

   • in the late 20th century, coal consumption started to decline due to - shift to North sea oil and gas, environmental concerns, closure of unprofitable coal mines and 1984-85 miner’s strike

   • deindustrialisation - many energy intensive industries declined, reducing emissions from heavy industry

   • reduction in C02 emissions from the fossil fuels due to the global financial crisis of 2009

UK timeline - transition policies and rise of renewables

Transition policies:

• 2000s onwards - policies like the climate change act 2008 set ambitious targets to reduce carbon emissions

• renewables and natural gas gained traction as cleaner energy sources

• improvements in technology and energy efficiency reduced energy consumption and emissions

Rise of renewables:

• investments in wind, solar, and other renewables surged, with offshore wind becoming a key contributor

• improved energy efficiency reduced overall energy demand

• development of nuclear power stations (particularly in the 1970s and 1980s)

UK timeline - coal-free milestones and end of coal power and net zero goals

Coal-free milestones and the modern low emission era:

• in 2015 - coal provided 22% of UK electricity, but this fell rapidly

• The UK achieved its first coal-free day in 2017

• by 2020, coal accounted for less than 2% of electricity

• 2014 - UK’s carbon emissions fell by 9% on the previous year due to fall in energy demand because of mild winter and spring

• 2019 - an unprecedented 40% of electricity generation came from renewables

• consumption-based CO2 emissions fell by around 21% over the past decade and total emissions by 29%

End of coal power and net zero goals:

• Most coal power plants have been decommissioned or converted to biomass

• the government committed to phasing out unabated coal power by 2024, later moving the deadline to 2025

• the UK’s commitment to achieving net-zero carbon emissions by 2050 has driven ambitious policies, including electrification of transport and the decarbonisation of heating

• Hornsea 1, coast of Essex, is the largest offshore wind farm in the world with a capacity of 1200 MW supplying 1 million homes

UK’s energy mix of C02 emissions in 2019

Natural gas - 38%

Oil - 38%

HEP and other renewables - 11%

Nuclear - 8%

Coal - 5%

China - contribution of China to anthropogenic GHG emissions pt 1

• Until the 1970’s, the countrys economy was overwhelmingly rural despite China’s huge population

• With an economy largely dependent on biofuels, total emissions of carbon from fossil fuels were modest

• after 1978, there was an abrupt U-turn of policy by China’s leaders moved the country away from a strict command economy and the country embraced the free market

• economic liberalisation simulated international trade and foreign direct investment

• Thus, China emerged as a major player in the global economy, with an economic growth based on export-led manufacturing

• by 2019, China controlled 17.5% of the worlds exports, compared to just 1% in 1970

China - contribution of China to anthropogenic GHG emissions - pt.2

• Industrialisation was accompanied by spectacular urbanissation; involving hundred of millions of people, the migration from rural to urban areas i China in the past 40 years was the largest population movement in history

• economic progress has raised average incomes to unprecedented levels

• GDP per capita rose from $299 in 1980 to $12,800 in 2012

• China’s economic development and industrialisation were made possible by massive energy consumption

• most of this energy came from the country;s huge indigenous reserves of coal. Inevitably, this produced large increases in carbon emissions

• unhampered by international protocols like Kyoto, carbon emissions rose by 2 and ½ times in period 2000-14

• in 2020, China consumed over 4 billion tonnes of coal; more than half the global consumption

• in 2006, it overtook the USA as the world’s largest emitter of carbon

• The Longyangxia solar farm generating 850MW and the wind farm at Gansu generation 8,000MW are making a difference, but coal still provides nearly 2/3rd of China’s energy

• China’s aim to reduce CO2 emissions by 60% of 2015 levels by 2030 appears to have little chance of success

China’s energy mix of CO2 emissions in 2017

Coal - 60%

Oil - 19%

HEP and other renewables - 12%

Natural gas - 7%

Nuclear - 2%

Evaluation of case studies between countries

• emissions are embedded, due to consumerism and globalisation, our emissions are increased in other countries as industry in the UK are practically non-existent

What is the UK’s carbon footprint:

• This value is the estimate of the GHG released globally to produce goods and services finally consumed by UK residents

• Nearly 50% of the UK’s carbon footprint is emitted abroad - 19% of this comes from China, 11% from the USA, and 6% from Germany, on aggregate, 36% comes from other European countries

Has the UK reduced its carbon emissions:

• a countries contribution to climate change can be measured in different ways

  • a production perspective - measures the emissions released within the UK, from UK factories, buildings, cars etc.

  • a consumption perspective (or carbon footprint) measures emissions released globally to satisfy the demand of UK residents

• Emissions from the UK production were 45% lower