Questions people actually ask

Climate change is a large-scale, long-term shift in the planet’s weather patterns and average temperatures. Met Office: What is climate change? NASA describes climate change as a long-term change in the average weather patterns that define Earth’s local, regional and global climates. NASA Science: What is climate change?

Global warming means the long-term heating of Earth’s surface seen since the pre-industrial period (1850 to 1900), caused mainly by burning fossil fuels. NASA Science: What is climate change? NASA points out that “climate change” and “global warming” are often swapped around but do not mean quite the same thing. NASA Science: What is climate change?

The Met Office says the evidence is clear: the main cause of climate change is burning fossil fuels such as oil, gas and coal. Met Office: Causes of climate change The IPCC’s 2021 report says human activity is unequivocally the cause of climate change. Met Office: What is climate change?

Since the Industrial Revolution the planet’s average temperature has risen by around 1.1 °C (IPCC Sixth Assessment Report). Met Office: What is climate change? For 2024, the World Meteorological Organization’s estimates of the current warming level ranged from 1.34 °C to 1.41 °C. Met Office: What is climate change?

Greenhouse gases act like a blanket round the Earth: sunlight passes through, the ground warms and gives off infrared heat, and some of that heat is caught and sent back down. Met Office: What is climate change? The greenhouse effect itself is vital: without it the Earth would be bitterly cold and people could not survive. Met Office: What is climate change?

The Keeling Curve, devised by Charles David Keeling of the Scripps Institution of Oceanography, charts carbon dioxide at Mauna Loa since 1958. Encyclopaedia Britannica: Keeling Curve It is the longest unbroken instrument record of carbon dioxide in the world. Encyclopaedia Britannica: Keeling Curve

Global average carbon dioxide reached 422.8 parts per million in 2024, a new record. NOAA Climate.gov (archived June 2025): Atmospheric carbon dioxide Carbon dioxide is now 50% higher than before the Industrial Revolution. NOAA Climate.gov (archived June 2025): Atmospheric carbon dioxide

Since record-keeping began in 1880, the hottest year in NASA’s record is 2024. NASA: Global temperature (vital sign) The 10 most recent years are the warmest on record (NASA). NASA: Global temperature (vital sign)

Between 1901 and 2018 the global average sea level rose by around 20 centimetres. Met Office: Effects of climate change Sea level rise is speeding up: from 1.4 mm a year through most of the 20th century to 3.6 mm a year in 2006–2015. NOAA Climate.gov (archived June 2025): Global sea level

The poles warm faster than other places: less ice means less sunlight reflected back to space, so the area heats up and more ice melts. Met Office: Effects of climate change Between 1979 and 2024, end-of-summer Arctic sea ice shrank by 12.1% per decade compared with the 1981–2010 average. NOAA Climate.gov (archived June 2025): Arctic sea ice

The Paris Agreement was adopted in Paris in December 2015, and was meant to improve on and replace the Kyoto Protocol. Encyclopaedia Britannica: Paris Agreement Its goal is to keep warming well below 2 °C above pre-industrial levels, and to try to limit it to 1.5 °C. United Nations: The Paris Agreement 195 Parties (194 States plus the European Union) have joined the Paris Agreement. United Nations: The Paris Agreement

In future the UK can expect warmer, wetter winters, hotter, drier summers, and more frequent and intense weather extremes. Met Office: Climate change in the UK Compared with 1990, by 2070 on a high-emissions path, UK winters could be 1–4.5 °C warmer and up to 30% wetter, and summers 1–6 °C warmer and up to 60% drier. Met Office: Climate change in the UK