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’s 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°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 Months J F M A M J J A S O N D Source: NOAA Replay

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’s 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 Canada Greenland Russia UK USA Median (1981-2010) Sea ice extent (minimum) Arctic sea ice min. extent: 1980, 7.8 million sq km. 2015, 4.6 million sq km 1980 1985 1990 1995 2000 2005 2010 2015 Source: National Snow and Ice Data Center Replay

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 (1986–2005 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)