Six graphics that explain climate change
A breakthrough deal to attempt to limit global temperature rises was agreed at a conference of world nations in December 2015. These charts from the time show how and why the Earth鈥檚 climate is changing.
1. What is the problem?
The world is getting warmer
The average temperature of the Earth's surface has increased by about 0.85掳C (1.4F) in the last 100 years. Up until 2015, 13 of the 14 warmest years had been recorded in the 21st Century. 2015 then became the hottest year on record, but was surpassed by record-breaking 2016.
How years compare with the 20th Century average
2015
is the coldest year on record
is the second coldest year on record
is the third coldest year on record
is the fourth coldest year on record
is the fifth coldest year on record
is the sixth coldest year on record
is the seventh coldest year on record
is the eighth coldest year on record
is the ninth coldest year on record
is the tenth coldest year on record
is the warmest year on record
is the second warmest year on record
is the third warmest year on record
is the fourth warmest year on record
is the fifth warmest year on record
is the sixth warmest year on record
is the seventh warmest year on record
is the eighth warmest year on record
is the ninth warmest year on record
is the tenth warmest year on record
10 warmest years
10 coldest years
20th Century average temperature
Hotter
Colder
Source: NOAA
2. Why is this happening?
Greenhouse gases, mainly carbon dioxide
Scientists believe that gases released from industry and agriculture (known as emissions) are adding to the natural greenhouse effect, the way the Earth's atmosphere traps some of the energy from the Sun.
Human activities such as burning fossil fuels like coal, oil and natural gas are increasing the amount of carbon dioxide (CO2), the main greenhouse gas responsible for global warming. Carbon-absorbing forests are also being cut down.
The concentration of CO2 in the atmosphere is now higher than at any time in the last 800,000 years and reached a record high in May 2015. But 2016 marked five consecutive years of CO2 increases of at least two parts per million.
Monthly average CO2 concentration (parts per million)
Scripps CO2 Program, data from the Mauna Loa Observatory
3. What are the effects?
Arctic sea ice melt
Higher temperatures, extreme weather events and higher sea levels are all linked to a warming climate and could have a drastic effect on the world鈥檚 regions.
Since 1900, sea levels have risen by on average about 19cm globally. The rate of sea-level rise has accelerated in recent decades, placing a number of islands and low-lying countries at risk.
The retreat of polar ice sheets is an important contributor to this rise.
Arctic sea ice is also shrinking because of higher temperatures, though it makes little contribution to raised sea levels.
An area of sea ice roughly 10 times the size of the UK has been lost when the current day is compared with average levels from the early 1980s.
1980
1985
1990
1995
2000
2005
2010
2015
Arctic sea ice min. extent: 1980, 7.8 million sq km. 2015, 4.6 million sq km
Source: National Snow and Ice Data Center
4. What does the future hold?
Higher temperatures and more extreme weather
The scale of potential impacts is uncertain.
The changes could drive shortages in freshwater, bring about major changes in food production conditions and cause a rise in the number of casualties from floods, storms, heat waves and droughts.
This is because climate change is expected to increase the frequency of extreme weather events - however linking any single event to global warming is complicated.
Projected temperature change (1986鈥�2005 to 2081-2100)
If greenhouse gas emissions peak between 2010-2020 and then decline substantially (RCP2.6)
If greenhouse gas emissions continue to rise throughout the 21st century (RCP8.5)
Source: International Panel on Climate Change - Fifth Assessment Report (AR5)
5. What can be done?
World鈥檚 top ten greenhouse gas emitters
The top 10 greenhouse gas emitters make up over 70% of total emissions
Source: Carbon Brief, figures are for 2012
6. Limiting the damage
By the end of October 2015, 146 countries had submitted national climate plans on curbing emissions that are expected to form the cornerstone of a binding, global treaty on climate change.
According to a UN report, submissions in their current form point to a rise of 2.7掳C above pre-industrial levels by 2100.
Scientists have determined that if temperature rises surpass 2掳颁, this will lead to substantial and dangerous climate impacts, which will hit the world's poor in particular.
Average warming (掳C) projected by 2100
Source: Climate Action Tracker, data compiled by Climate Analytics, ECOFYS, New Climate Institute and Potsdam Institute for Climate Impact Research.
