Key Facts about Emissions leading to Climate Change & Environmental Issues

• Carbon dioxide emissions are the primary driver of global climate change. It’s widely recognised that to avoid the worst impacts of climate change, the world needs to urgently reduce emissions.
• Prior to the Industrial Revolution, emissions were very low and it was still relatively slow until the mid-20th century. In 1950 the world emitted 6 billion tonnes of CO2 but by 1990 this had almost quadrupled, reaching more than 22 billion tonnes.
• Emissions have continued to grow rapidly; we now emit over 34 billion tonnes each year.
• Well into the 20th century, global emissions were dominated by Europe and the United States. In 1900, more than 90% of emissions were produced in Europe or the US and by 1950, they accounted for more than 85% of emissions each year.
• In the second half of the 20th century we see a significant rise in emissions in the rest of the world, particularly across Asia, and most notably, China.
• The US and Europe now account for just under one-third of emissions.
• The world’s largest per capita CO2 emitters are the major oil producing countries mostly in the Middle East with relatively low population size.: In 2017 Qatar had the highest emissions at 49 tonnes (t) per person, followed by Trinidad and Tobago (30t); Kuwait (25t); United Arab Emirates (25t); Brunei (24t); Bahrain (23t) and Saudi Arabia (19t).
• More populous countries with some of the highest per capita emissions – and therefore high total emissions – are the United States, Australia, and Canada. Australia has an average per capita footprint of 17 tonnes, followed by the US at 16.2 tonnes, and Canada at 15.6 tonnes - more than 3 times higher than the global average, which in 2017 was 4.8 tonnes per person.
• Many countries across Europe, for example, have much lower emissions than the US, Canada or Australia and nnot far from the global average: In 2017 emissions in Portugal were 5.3 tonnes; 5.5t in France; and 5.8t per person in the UK. This is also much lower than some of their neighbours with similar standards of living, such as Germany, the Netherlands, or Belgium. The choice of energy sources plays a key role here: in the UK, Portugal and France, a much higher share of electricity is produced from nuclear and renewable sources and a much lower share of is produced from fossil fuels: in 2015, only 6% of France’s electricity came from fossil fuels, compared to 55% in Germany.
• Many countries in the world still have very low per capita CO2 emissions like in the poorest countries in Sub-Saharan Africa – such as Chad, Niger and the Central African Republic – the average footprint is around 0.1 tonnes per year. That’s more than 160 times lower than the USA, Australia and Canada.

In just 2.3 days the average American or Australian emits as much as the average Malian or Nigerien in a year.

• Asia is by far the largest emitter, accounting for 53% of global emissions. As it is home to 60% of the world’s population this means that per capita emissions in Asia are slightly lower than the world average, however.
• China is, by a significant margin, Asia’s and the world’s largest emitter: it emits nearly 10 billion tonnes each year, more than one-quarter of global emissions.
• North America – dominated by the USA – is the second largest regional emitter at 18% of global emissions. It’s followed closely by Europe with 17%.
• Africa and South America are both fairly small emitters: accounting for 3-4% of global emissions each.
• India is the 3rd largest emitter of CO2 after China and the US.
• China, the USA and the EU account for more than half of global emissions.
• Since 1751 the world has emitted over 1.5 trillion tonnes of CO2.

Biggest Emitters, by Country

Asia, led by China, is the largest emitter, with the continent accounting for more than half of global emissions.

Key Stats

• The US has emitted more CO2 than any other country to date: at around 400 billion tonnes since 1751, it is responsible for 25% of historical emissions - this is twice more than China – the world’s second largest national contributor.
• The 28 countries of the European Union (EU-28) is also a large historical contributor at 22%. In contrast, most countries across Africa have been responsible for less than 0.01% of all emissions over the last 266 years.
• Many of the large annual emitters today, like, India and Brazil are not large contributors in a historical context.
• Africa’s regional contribution – relative to its population size – has been very small. This is the result of very low per capita emissions – both historically and currently.
• Up until 1950, more than half of historical CO2 emissions were emitted by Europe. The vast majority of European emissions back then were emitted by the United Kingdom - until 1882 more than half of the world’s cumulative emission.
• Over the century which followed, industrialization in the USA rapidly increased its contribution.
• It’s only over the past 50 years that growth in South America, Asia and Africa have increased these regions’ share of total contribution.
• Countries with the highest emissions over history are not always the biggest emitters today. The UK, for example, was responsible for only 1% of global emissions in 2017.
• This inequality in historical and current emissions is one of the main reasons which makes international agreement on who should take action so challenging.

Consumption Base (Trade Adjusted) Emissions

Which countries in the world are net importers of emissions and which are net exporters?

• The USA’s net import of CO2 is equivalent to 7.7% of its domestic emissions. This means emissions calculated on the basis of ‘consumption’ are 7.7% higher than their emissions based on production.
• China’s net export of CO2 is equivalent to 14% of its domestic emissions. The consumption based emissions of China are 14% lower than their production-based emissions.
• Most of Western Europe, the Americas, and many African countries are net importers of emissions whilst most of Eastern Europe and Asia are net exporters.

Consumption Based Emissions Compared To Production Based Emissions

• Consumption based emissions of the US are higher than production: In 2016 the two values were 5.7 billion versus 5.3 billion tonnes – a difference of 8% IE This more CO2 is emitted in the production of the goods that Americans import than in those products Americans export.
• The opposite is true for China: its consumption based emissions are 14% lower than its production-based emissions. On a per capita basis, the respective measures are 6.9 and 6.2 tonnes per person in 2016.
• Whilst China is a large CO2 emissions exporter, it is no longer a large emitter because it produces goods for the rest of the world.
• Some countries have only achieved emissions reductions by offshoring emissions intensive production to other countries like Ireland in the early 2000s; Norway in the late 1990s and early 2000s; and Switzerland since 1990.
• On the other hand there are several very rich countries where both production- and consumption-based emissions have declined. This has been true, among others, for the UK, France, Germany, and the USA. These countries have achieved some genuine reductions without outsourcing the emissions to other countries.

Decoupled economic growth from CO₂emissions

• The UK’s GDP has increased a lot over the last 30 years, while its emissions have fallen. Many countries have achieved this decoupling like France, Germany, Sweden, Finland, Denmark, Italy, Czech Republic and Romania.
• There are two key reasons why emissions have fallen in these countries. First, some countries have managed to decouple energy use and economic growth. GDP has increased while total energy use has remained flat, or even fallen. But the second is the most important: countries are replacing fossil fuels with low-carbon energy proving we can produce more energy, without the emissions that used to come with it.

Global Inequalities in CO2 Emissions

• In terms of income, the richest half (high and upper-middle income countries) emit 86% of global CO2 emissions whereas the bottom half (low and lower-middle income) only 14%. The poorest countries (9% of the global population) are responsible for just 0.5%.
• When aggregated by region we see that North America, Oceania, Europe, and Latin America have disproportionately high emissions relative to their population. North America, home to only five% of the world population emits nearly 18% of CO2 (almost four times as much). Asia and Africa are underrepresented in emissions. Asia is home to 60% of the population but emits just 49%; Africa has 16% of the population but emits just 4% of CO2. This is reflected in per capita emissions; the average North American is more than 17 times higher than the average African.
• This inequality in global emissions lies at the heart of why international agreement on climate change has (and continues to be) so contentious. The richest countries of the world are home to half of the world population, and emit 86 % of CO2 emissions.

Global Inequalities in CO2 Emissions – By Consumption

Consumption-based emissions are: (production-based emissions – embedded CO2 in exported goods + embedded CO2 in imported goods).

• High income countries’ collective emissions increase from 39 to 46 % when adjusted for trade (with only 16 % of the population); upper-middle income countries’ emissions decrease by the same amount (7 %age points) from 48 to 41 %. Overall, this balances out in the top half of the world population: upper-middle income countries are net exporters whilst high income, net importers.
• Traded emissions tend to flow from Asia to North America and Europe (Asia’s share reduces when adjusted for trade whilst North America and Europe’s share increases).

Annual greenhouse gas emissions: how much do we emit each year?

• Total greenhouse gas emissions are the sum of emissions of various gases: carbon dioxide, methane, nitrous oxide, and smaller trace gases such as hydrofluorocarbons (HFCs) and sulfur hexafluoride (SF6), measured in CO2 equivalents.
• Today, we collectively emit around 50 billion tonnes of CO2e each year. This is more than 40% higher than emissions in 1990, which were around 35 billion tonnes.
• As is the case with CO2 emissions, China is the world’s largest emitter of greenhouse gases today. It emits around twice as much as the United States, which is the second largest emitter. This is followed by India, Indonesia and Russia.
• Many of the world’s smaller countries are the largest per capita emitters. These countries, such as Guyana, Brunei, Botswana, the United Arab Emirates and Kuwait tend to be large oil and/or gas producers.
• Of the major emitters we see large differences in per capita emissions: in the US, the average person emits more than 18 tonnes; in China its less than half, at 8 tonnes; and in India, emissions are much smaller at around 2.5 tonnes.

Where does methane come from?

Agriculture, fossil fuel production, and the management of waste are the primary sources of methane emissions:

• Livestock (ruminant animals – cattle, goats, and sheep) produce methane through a process called ‘enteric fermentation’.
• Rice cultivation produces methane – waterlogged paddy fields provide an ideal environment for microbes to produce methane in a process called ‘methanogenesis’.
• Biomass burning: methane is produced from the incomplete combustion of large-scale burning of woodlands, savanna and agricultural waste.
• Waste: the decomposition of organic waste in landfills produces methane.
• Fossil fuel production: methane can be released during oil and gas extraction – a category often termed ‘fugitive emissions’.
• Methane is a much stronger greenhouse gas than CO2 - one tonne of methane would generate 28 times the amount of global warming as one tonne of CO2
• Most of our nitrous oxide emissions come from agriculture: N2O is produced when we apply nitrogen fertilizers to soils.
• Nitrous oxide is a much stronger greenhouse gas than CO2- one tonne of nitrous oxide would generate 265 times the amount of warming as one tonne of CO2.
• The average ‘lifetime’ of nitrous oxide in the atmosphere is around 121 years.
• This is typically shorter than CO2 (which can persist for centuries or even thousands of years), but longer than methane (which has an average lifetime of 12 years).

Emissions By Sector: Where do our Emissions come from?

Energy (electricity, heat and transport): 73.2%

Energy use in industry: 24.2%

Iron and Steel (7.2%):

Chemical & Petrochemical (3.6%): Fertilizers, pharmaceuticals, oil and gas extraction etc.

Food and tobacco (1%): Tobacco products and food processing

Non-ferrous metals: 0.7%: Aluminium, copper, lead, tin, zinc etc…

Paper & pulp (0.6%): Conversion of wood into paper and pulp.

Machinery (0.5%): Production of machinery.

Other industry (10.6%): Including mining, construction, textiles, wood products etc.

Transport: 16.2%

Road transport (11.9%): 60% emissions are from passenger travel (cars, motorcycles, buses etc.) and 40% from road freight (lorries and trucks).

If we could electrify the whole transport sector, we could reduce global emissions by 11.9%.

Aviation (1.9%): 81% of aviation emissions come from passenger travel and 19% from freight.

Shipping (1.7%): Emissions from passenger and freight boats.

Rail (0.4%): Emissions from passenger and freight rail travel.

Pipeline (0.3%): Transportation of fuels and commodities (oil, gas etc.) within or between countries via pipelines.

Energy use in buildings: 17.5%

Residential buildings (10.9%): Electricity for lighting, appliances, cooking etc. and heating at home.

Commercial buildings (6.6%): Electricity for lighting and heating in offices, restaurants etc..

Unallocated fuel combustion (7.8%)

Fugitive emissions from energy production: 5.8%.

Fugitive emissions from oil and gas (3.9%): Leakage of methane during oil and gas extraction and transportation from damaged pipes and flaring – the intentional burning of gas at oil facilities.

Fugitive emissions from coal (1.9%): Accidental leakage of methane during coal mining.

Energy use in agriculture and fishing (1.7%): From the use of machinery in agriculture and fishing.

Direct Industrial Processes: 5.2%

Cement (3%):

Chemicals & petrochemicals (2.2%):

Waste: 3.2%

Wastewater (1.3%): Decomposition of organic matter and residues from animals, plants, humans and their waste products.

Landfills (1.9%): OnDecomposition of organic matter in Landfills.

Agriculture, Forestry and Land Use: 18.4%

Agriculture, Forestry and Land Use accounts for 18.4% of greenhouse gas emissions. The food system as a whole – including refrigeration, food processing, packaging, and transport – accounts for around one-quarter of greenhouse gas emissions.

Grassland (0.1%): When grassland becomes degraded, the soil loses carbon, converting to carbon dioxide.

Cropland (1.4%): Through bad management practices used on croplands, carbon is lost or sequestered into soils and biomass.

Deforestation (2.2%): Net emissions of carbon dioxide from changes in forestry cover.

Crop burning (3.5%): – Farmers often burn crop residues after harvest to prepare land for the re-sowing of crops, this releases carbon dioxide, nitrous oxide and methane.

Rice cultivation (1.3%): Flooded paddy fields produce methane through a process called ‘anaerobic digestion’ but then rice accounts for around one-fifth of the world’s supply of calories, and is a staple crop for billions of people globally.

Agricultural soils (4.1%): Nitrous oxide is produced when nitrogen fertilizers are applied to soils for agricultural products – including food for direct human consumption, animal feed, biofuels and other non-food crops (such as tobacco and cotton).

Livestock & manure (5.8%): Animals like cattle and sheep produce greenhouse gases through a process called ‘enteric fermentation’ (when microbes in their digestive systems break down food, they produce methane as a by-product). So beef and lamb have a high carbon footprint, and eating less is an effective way to reduce the emissions of your diet.

Nitrous oxide and methane are also produced from the decomposition of animal manures under low oxygen conditions. This occurs when large numbers of animals are managed in a confined area (such as dairy farms, beef feedlots, and swine and poultry farms), where manure is typically stored in large piles or disposed of in lagoons and other types of manure management systems.

• Electricity and heat production are the largest contributor to global emissions followed by transport, manufacturing and construction (cement and similar materials) and agriculture.

This is not the same everywhere, in the US, for example, transport is a much larger contributor than the global average. In Brazil, the majority of emissions come from agriculture and land use change.

• Food production is responsible for one-quarter of the world’s greenhouse gas emissions

You want to reduce the carbon footprint of your food? Focus on what you eat, not whether your food is local

Food is responsible for approximately 26% of global GHG emissions.

• Livestock & fisheries account for 31% of food emissions.
  Livestock – animals raised for meat, dairy, eggs and seafood production
• Crop production accounts for 27% of food emissions.
  21% of food’s emissions comes from crop production for direct human consumption, and 6% comes from the production of animal feed.
• Land use accounts for 24% of food emissions.
  Twice as many emissions result from land use for livestock (16%) as for crops for human consumption (8%).
• Supply chains account for 18% of food emissions.
  Food processing (converting produce from the farm into final products), transport, packaging and retail all require energy and resource inputs.

Food waste is responsible for 6% of global greenhouse gas emissions

• Around one-quarter of the calories the world produces are thrown away - they’re spoiled or spilled in supply chains or are wasted by retailers, restaurants and consumers. To produce this food we need land, water, energy, and fertilizer inputs, so it all comes at an environmental cost.
• Almost one-quarter – 24% – of food’s emissions come from food that is lost in supply chains or wasted by consumers.
• This means that food wastage is responsible for around 6% of total global greenhouse gas emissions.In fact, it’s likely to be slightly higher since the analysis from Poore & Nemecek (2018) does not include food losses on the farm during production and harvesting.
• To put this in context: it’s around three times the global emissions from aviation or, if we were to put it in the context of national emissions, it would be the world’s third largest emitter.Only China (21%) and the United States (13%) emitted more.

(Data on Emissions, GHGs and Climate Impacts is sourced from: IPCC - The Intergovernmental Panel for Climate Change, Global Carbon Budget, Carbon Management , Earth System Science Data, Our World in Data, Geophysical Research Letters, Science, The World Resources Institute, The International Council of Clean Transportation and Swedish Institute for Food and Biotechnology)