The report found unequivocal evidence that observed warming of the climate is a consequence of emissions from human activity that has increased the concentration of greenhouse gases in the global atmosphere. Human induced climate change has already affected the severity and frequency of many types of extreme weather and climate events.

Recent decades in the UK have been warmer, wetter and sunnier than in the 20th century, with 2020 being the third warmest, fifth wettest and eighth sunniest year since records began in 1884.

The global and UK response to climate change has two main elements:

• ‘Mitigation’ or reducing emissions of greenhouse gases which lead to global warming. This includes reducing energy consumption and changing to low emission energy sources.
• ‘Adaptation’ to climate change and the extreme weather that it makes increasingly likely. This includes planting different tree species based on expected pests and diseases from higher temperatures and making our homes more resilient to extreme heat and cold weather.

Climate and weather in the UK

Temperature

The UK’s warming has been broadly consistent, though slightly higher, than the increases in global mean temperature. The decade from 2011 to 2020, was 1.1°C warmer on average in the UK than the 1961 to 1990 average.

While all the top 10 warmest years since 1884 have occurred this century (Figure 1), all of the top 10 coldest years occurred before the 21st century. The UK’s coldest year this century was 2010, which was the 22nd coldest since 1884.

Rainfall

The decade from 2011 to 2020 was on average 4% wetter than the period 1981 to 2010, and 9% wetter than 1961 to 1990.

Six of the UK’s ten wettest years in a series going back to 1862 have occurred since 1998: in order of the wettest these were 2000, 2020, 2012, 1998, 2008 and 2014 (Figure 2). For the decade 2011 to 2020, UK summers have been on average 17% wetter than 1961 to 1990 and the UK winters have been 19% wetter. The wettest ever months of February, April, June, November and December on record in the UK have all been since 2009, in a series going back to 1862.

Growing season

The thermal growing season is based on temperature, rather than other factors affecting plant growth like rainfall, soil moisture and frost. It is the number of days between the first 6-day period of daily mean temperatures above 5°C and the first 6-day period after 1 July where the daily mean temperature is below 5°C. The growing season in 2020 was 319 days.

The UK’s warming climate has seen the average growing season length increase (Figure 3). The average growing season in the decade 2011 to 2020 was 29 days longer than the 1961 to 1990 average.

Greenhouse gas emissions

There are three main measures of UK emissions of greenhouse gases: territorial, residence, and footprint also known as consumption. In 2018, the latest year with figures for all three measures, total emissions ranged from 468 million tonnes of carbon dioxide (CO2) equivalent on a territorial basis to 703 million tonnes of CO2 equivalent on a consumption basis (Figure 4). For more information on different UK greenhouse gas emissions measures, see Measuring greenhouse gas emissions.

Mitigation

The Climate Change Committee, an independent statutory body to advise UK and devolved governments, refers to climate change mitigation as actions aimed at avoiding further climate change from occurring.

Energy demand

Primary energy demand is the energy the UK needs for consumption and for operating oil refineries and power stations. This has fallen since 2000.

The UK’s energy mix has shifted away from the use of coal (Figure 5). Coal met 16% of energy demand whilst renewables met only 1% in 2000, and by 2020 coal was meeting 3% and renewable energy 16%, mainly through bioenergy and wind. Fossil fuels remain important, including oil for transport and gas for energy generation and heating.

Energy intensity

Energy intensity is a measure of how much activity is achieved with a given amount of energy, so is an indicator of efficiency.

Since 2000, there have been efficiency improvements in road passenger transport with the energy required per passenger kilometre travelled falling 7.6% between 2000 and 2018, reflecting the better fuel economy of cars. Household and service efficiency has also improved over the last twenty years (Figure 6), driven by increasingly efficient space heating (for example, new combi boilers are significantly more efficient than older ones), greater insulation in homes and businesses, and a wholesale change in lighting efficiencies.

Primary Energy Consumption is the amount of fuel used before any loss of energy occurs through conversion or transformation. The Primary energy equivalent includes fuel use after accounting for any losses incurred during the energy transformation process, such as electricity generation and oil refining. Primary energy intensity is calculated by dividing primary energy consumption by Gross Domestic Product (GDP). Primary energy consumption declined 30% between 2000 and 2020, leading to a drop in primary energy intensity of over 43% (Figure 7), while UK GDP grew 24% over the same period.

Adaptation

While mitigation seeks to avoid further climate change, adaptation describes actions taken to reduce the negative impacts of climate change already happening and expected in the future by building resilience to climate change.

The UK is taking measures to adjust to the changing climate, including adapting homes so they are more resilient, making our water resources more resilient and increasing the area of the UK that is woodland with future warming in mind.

Woodlands

UK woodlands are important for mitigation. New woodlands can sequester carbon at a higher rate than other semi-natural habitats. They become a significant carbon store as they age, generally taking ten to thirty years to become significant sinks of carbon. See the Woodland Carbon Code for more details on sequestering and storing carbon potential of native broadleaved woodlands.

Woodland also need to be resilient to changes due to a warming climate, such as new pests and diseases and changing rain patterns. The Forestry Commission’s research agency, Forest Research, has highlighted the importance of having the right trees in the right places. The Commission has produced a guide and a climate matching tool to see what new trees are best suited for a location, ensuring trees planted are appropriate for both the future and current climates.

Benefits from individual trees and green spaces in urban areas include urban cooling within the UK. During periods of high temperatures, air temperatures within greenspaces are typically lower than those in surrounding built-up areas.

UK woodland area

The land area of the UK covered by woodland increased from 9% in 1980 to 13% in 2021 (Figure 8). Over 13,000 hectares of new woodland were created in the UK in the year to March 2021. Woodland is defined in these statistics as areas of 0.5 hectares or over, a width of greater than 20 metres and with a canopy cover of at least 20% (or having the potential to achieve this).

Woodland cover varies by UK nation, from 19% of Scotland, 15% of Wales, 10% of England and 9% of Northern Ireland. Shares of woodland area also vary considerably at local level. Figure 9 shows the percentage of woodland by Local Authority in 2019. Neath Port Talbot has the highest estimated woodland cover at 39%. Some of the areas with very low woodland cover - Orkney Island (0.2%) and Fenland district in Cambridgeshire (0.5%) - both have peatlands, which are a significant carbon store like trees. Peatland and heathland, sites with rare or protected species and archaeological sites are all areas unsuitable for woodland planting.

As at March 2021, 51% of UK woodland was conifers (species such as spruce, pine and larch) and 49% broadleaf (species such as oak, birch and beech) (Figure 10) .

Over the last 45 years, the type of new trees planted has changed. In the mid-1980s, around 5% of new woodland creation was broadleaf, rising to more than 80% between 2005 and 2010. In the last five years (2017 to 2021), 40-45% of new woodland planting was broadleaf. New woodland refers to areas of land that were not previously woodland.

Water resources

Climate change and a growing population places increasing pressure on water supplies. Reductions in water consumption and leakage can help ensure supplies.

A key water system leakage measure is a 3-year average, with sensitivity to periods of extreme weather, for example, Northern Ireland Water identified the winter freeze and subsequent thaw from December 2009 to February 2010 had a significant impact on water leakage.

Each of the four UK nations has shown a steady decrease in water lost through leakage (Figure 11). Scotland has reduced this by 52% between the 3 years ending 2007-08 and the 3 years ending 2019-20, and Wales by 23%, England by 9% and Northern Ireland by 3% over the same period.

Water consumption per capita in England has also fallen from an average of 152 litres per person per day in the 3 years to 2003-04 to an average of 141 litres per person per day in the 3 years to 2019-20 (Figure 12).

Energy efficiency in homes

Energy Performance Certificates (EPCs) give homes an energy efficiency rating from ‘A’, being the most efficient to ‘G’, being the least efficient. A higher rating usually means lower fuel bills.

In 2020, only 3% of new EPCs recorded for existing homes in 2020 were in the two most energy efficient ratings, ‘A’ or ‘B’ (Figure 13). The middle rating (‘D’) accounted for 42% of the total in that year.

By contrast, 89% of new buildings in 2020 were rated ‘A’ or ‘B’ (Figure 14).

Contact details for this article: climate.change@ons.gov.uk