Climate change in the UK

Contents

In this article, we'll use our UK Climate Projections (UKCP) to see how climate change might affect the UK. UKCP is our climate projection toolkit, which looks at how the UK climate may change in the future.

It's important to remember that by reducing emissions, we can avoid some of the changes we’ll talk about in this article.

We use ranges and probabilities to project the future. Even for a given level of emissions, there is some uncertainty in how the climate will respond. We try to estimate this uncertainty by running several model simulations. This gives us a range of likely changes.

Modelling climate change is a very complex and important part of what we do. You can read more about how we do this at the end of this article, in climate change models.

The climate in the UK

The UK has a temperate maritime climate. In general, that means that we have a cool and mild climate, with changeable weather.

We all know the weather here can change quickly. It's not unusual for us to see many different weather conditions in one day.

Lots of different factors influence our weather. Warmer tropical air meets colder arctic air in the air mass above us. This is what causes the large changes in weather we experience and fuels our more severe storms.

So, how will climate change impact this? Will it change the weather we experience in the UK? If so, what sort of changes could we see? And how could that change our lives?

How will climate change affect the UK?

Across the UK, we expect to see:

  • Warmer and wetter winters
  • Hotter and drier summers
  • More frequent and intense weather extremes

Climate change will make these conditions more likely. The UK’s weather will continue to be variable, but we will see more of this type of weather.

In the future, we will still see a lot of the weather we experience today. The difference, though, is that the intensity of some weather types will change.

You may have heard of Spanish plumes, which bring hot conditions in the summer. We could see these become more intense, creating even hotter summer weather. But Spanish plumes could also bring more intense downpours during summer thunderstorms.

More rainfall could happen in winter storms, too. While the temperatures may be milder, winters will tend to be wetter, with more potential for flooding.

How will climate change affect your local area?

In 2020, we worked with the BBC to create a new way of visualising climate change in the UK.

This local climate change visualisation tool lets you explore climate projections in your local area. You can also compare these projections to the previous weather records in the region.

The tool uses different Met Office datasets to create this new look at climate change. Climate data and records come from the National Climate Information Centre (NCIC). Projections are from the latest UK Climate Projections, using the UKCP Regional (12km) data.

How much could the UK climate change?

Compared to our climate in 1990, by 2070 we project:

  • Winters are between 1 and 4.5°C warmer
  • Winters are up to 30% wetter
  • Summers are between 1 and 6°C warmer
  • Summers are up to 60% drier, depending on the region
  • Hot summer days are between 4 and 7°C warmer

We base these changes on the RCP8.5 high emissions scenario, where the world continues to create high levels of emissions.

These changes would bring lots of real-world impacts, which will affect our lives.

Hot spells and the risk to public health

Let's look at hot spells, for example. While many of us might look forward to hot summer days, they can be very dangerous.

Heatwaves are a risk to health and, in some cases, life. There is evidence that proves this across the world but also right here in the UK.

During the summer heatwave of 2003, there were over 2,000 excess deaths over a 10-day period. In a 2006 heatwave, the Government estimated 680 excess deaths. And in 2009, there were approximately 300 excess summer deaths.

Many of these excess deaths are among older people. These are not people who would have died due to illness or old age. There is strong evidence that these deaths are the result of heat-related conditions (source: Heatwave Plan for England)

Climate change will make hot spells more frequent and severe. By 2070, the chance of exceeding 30°C for two days or more increases—a lot. In fact, over the southern UK, it becomes sixteen times more frequent than it is today. That will have a large impact on our elderly population and public health.

That's prolonged heat, but extremes become more likely, too. By 2070, the chances of exceeding 40°C are similar to the chances of exceeding 32°C thirty years ago. For regions in the south, the average hottest day in summer could have temperatures reaching 40°C by the 2070s.

Increased rainfall and risk of flooding

In the future, we project the intensity of rain will increase. When we talk about intensity, we mean how heavy rainfall is when it occurs. In the summer, this could increase by up to 20%. In winter, it could increase by up to 25%.

Hourly rainfall exceeding 30mm per hour is a threshold used by the Met Office and the Environment Agency Flood Forecasting Centre to issue flash flood alerts. By 2070, we project we will meet this threshold twice as often as we did in 1990.

A greater risk of flooding will have large impacts, both on the environment and in our daily lives.

Quite simply, if we do not reduce emissions, this is a very real, potential future for our climate.

When will climate change affect the UK?

Change is already happening. Some variables, such as heavy rainfall, will take time before increases are clear, beyond natural variability.

It's important to remember that there are ranges of possible change. We can provide information on the probability that something will happen, but it isn’t guaranteed.

The further into the future we look, the more likely we are to see record hot temperatures or heavy rainfall events. This is more likely if we consider a high emissions scenario. That doesn't mean we won’t experience cold events; they will just occur less frequently.

Has the UK’s climate already changed?

We know that the UK has already warmed by 1°C since around the 1950s. We can see this in observations from our land-based weather stations. There are a lot of other ways we observe this change:

  • Increased temperature in coastal seas around the UK
  • Less frost and snow
  • Longer and more frequent warm and hot spells
  • Shorter and less frequent cold spells
  • Breaking many high temperature records

Effects of climate change in the UK

We've talked about how climate change might affect our climate and weather, with some very real and direct impacts.

More extreme heat, for example, will be a risk to public health. More frequent heatwaves will put people at risk, particularly older people.

Frequent and intense rainfall will cause an increase in flooding, which we will need to adapt to. We have all seen the devastation caused by flooding and how it can impact our lives.

Considering how we manage our land, where we build our homes and how best to defend against flooding will be critical in the years to come.

Already, the Government has pledged £5.2 billion for new flood and coastal defences by 2027. This money is part of the plan for a green industrial revolution, announced in November 2020.

Climate change will impact farming, too. Some crops may be easier to grow, and the growing season will expand. More droughts, though, will disrupt the growing season. Some of crops we grow today may not be suited to higher temperatures, too.

Climate statistics for the UK

2019 and 2020 saw many extreme weather events. This included storms, floods and heatwaves.

Some types of weather records are being broken more often than in recent decades.

Here are some of the statistics and records from recent years.

2019 UK climate records

Last year, we recorded four new national temperature records.

  • Hottest winter temperature (21.2°C)
  • Hottest summer temperature—and record high in the UK (38.7°C)
  • Hottest December temperature (18.7°C)
  • Hottest February minimum temperature (13.9°C)

You can find more information about the 2019 records here:

2020 UK climate records

This year, we've already seen plenty of extreme weather events.

Some of the things we've seen include:

  • Wettest February on record, which brought Storms Ciara and Dennis
  • The sunniest spring on record
    • 626 hours of bright sunshine
    • The previous record was 555 in 1948
  • Driest May on record for England
  • The third hottest day on record (37.8°C)
  • The wettest day on record in the UK overall, on 3 October

Climate record trends

We can also see trends, with recent years bringing lots of extremes:

  • 7 of the last 10 summers (2011-2020) have reached a temperature of 34°C
    • Before this, just 7 of the previous 50 summers (1961-2010) reached 34°C
  • 6 of the 10 wettest years on record have been since 1998

These records are not a definite sign of things to come. We also can't say that climate change caused them, but it does make them more likely.

The UK climate in 2070

Projections deal in probability, rather than definite outcomes. However, we can summarise some of the possible changes we've talked about so far.

Summer

Compared to the climate in 1990:

  • Summers are between 1 and 6°C warmer
  • Summers are up to 60% drier, depending on the region
  • The average hottest summer day is between 4 and 7°C warmer
  • The chance of exceeding 30°C for two days or more is sixteen times more likely in the south
  • The chance of exceeding 40°C is similar to the chance of exceeding 32°C in 1990
  • Intensity of rain increases by up to 20%
  • Days when rainfall exceeds 30mm per hour happen twice more often

Winter

Compared to the climate in 1990:

  • Winters are between 1 and 4.5°C warmer
  • Winters are up to 30% wetter
  • Intensity of rain increases by up to 25%

Climate change models

The UK Climate Projections (UKCP) are the Met Office's climate analysis and projection toolkit. The 2018 UKCP are the latest projections, which give us more detail than ever before. We use these projections to see how our climate may change over the coming decades.

UKCP uses new, state-of-the-art climate models. This lets us create global projections, as well as local projections in the UK.

The UKCP models are important in understanding the potential risks we face. This helps inform the UK's mitigation and adaptation strategies for climate change.

Probabilistic projections

We have probabilistic projections for a range of global temperature rises. We refer to these as the Representative Concentration Pathway, or RCP for short.

We have probabilistic projections available for:

  • RCP2.6
  • RCP4.5
  • RCP6.0
  • RCP8.5

These projections show us the relative chance of specific outcomes. For example, we can look at monthly mean temperature or rainfall in UK regions.

Many of the projections in this article use RCP8.5, which is a high temperature rise scenario. This is a pathway where greenhouse gas emissions keep accelerating. This is not inevitable, but a plausible scenario if we do not curb our emissions.

Global model

The global model projections give us 28 alternate views of the climate in the future. These projections are at a 60km resolution.

Here, we can look at a greater number of variables. We can use this to look at global climate impacts. For example, we can use it for risk assessments on global food supply chains.

Regional model

The regional model projections give us 12 alternate views of the climate. These projections are at a 12km resolution – a higher resolution than the global model.

These projections give us higher spatial detail and greater information about daily extremes.

Local model

The local model provides 12 alternate views but at even higher 2.2km resolution. This is the same resolution typically used for weather forecasting.

This is the first time that national climate scenarios have been available in this detail. It provides new national capability in assessing changes at local scales and for hourly extremes.

By using the local model, we can see things in much greater detail. It helps us see changes in local weather extremes, including:

  • Heavy summer downpours
  • Severe wind gusts
  • Hail
  • Lightning
  • Temperature extremes over cities