Changes in the climate

You may find these extracts from the Met Office and the defra web sites of interest:

"To understand climate change, it’s important to recognise the difference between weather and climate. Weather is the temperature, precipitation (rain, hail, sleet and snow) and wind, which change hour by hour and day by day. Climate is the average weather and the nature of its variations that we experience over time.

Human activities, like burning coal, oil and gas, have led to an increase in greenhouse gases in the atmosphere, causing an enhanced greenhouse effect and extra warming.

As a result, over the past century there has been an underlying increase in average temperatures which is continuing. Globally, the ten hottest years on record have all been since 1997.

What does it mean for the world?

Climate change will mean warmer temperatures which will change rainfall patterns, cause snow and ice to melt and affect the intensity of extreme weather such as storms and heatwaves. We have already begun to experience some of these impacts and many other knock-on effects:

• Water and food — around 1.5 billion people currently live in water-stressed regions. Climate change and population growth could increase this to seven billion by the 2050s, intensifying competition for this life-giving resource. Some areas could become more fertile; others more barren. This may lead to regional food shortages, mass migration and poverty. Malnutrition is expected to increase in developing countries. Source: IPCC 2007.
• Health — our well-being will be threatened by more frequent and intense heatwaves, floods, storms, wildfires and droughts. However, deaths from cold-related diseases will reduce. Patterns of disease will also change, with wide areas of the world at risk from major diseases, such as Dengue.
• Environment — coastal areas will experience more flooding from rising sea-levels, especially large river deltas which tend to be highly populated, e.g. the Nile Delta. Meanwhile, some areas will attract more tourism as their climates alter.
• Ecosystems — Amazonia is already damaged by deforestation. Climate change may magnify this impact by increasing the risk from fire. Other precious areas of high biodiversity, such as in South Africa, may see major losses of species as habitat conditions change. Around the world, some animals and plants may benefit and flourish in a changing climate, while others are likely to suffer.

What does it mean for the UK?

Even across relatively small areas like the UK, climate change is expected to cause marked regional differences in temperature and rainfall by the end of the 21st century.

How our climate has changed

1. Central England temperatures have increased by 1 °C since 1970s.
2. Total summer rainfall has decreased in most parts of the UK.
3. Sea surface temperature around the UK has risen by about 0.7 °C, over the past three decades.
4. The UK has experienced nine of the 10 warmest years on record since 1990.
5. Sea-levels around the UK have risen 10 cm since 1900.

How our climate may change

1. Under a medium emissions scenario, the annual average temperature rise by the end of the century is very likely to be more than 2 °C and less than 5 °C. The central estimate is 3.5 °C.
2. Temperatures are expected to rise across the UK with more warming in summer than in winter. The summer average temperature rise in the south-east is very likely to be above 2 °C and below 6.4 °C. The central estimate is 4 °C.
3. The urban heat island effect already warms central London by more than 10 °C on some nights. Increased urbanisation and release of waste heat would increase this still further — on top of the effects of global warming.
4. As summers become warmer and drier droughts are more likely, particularly in the south-east. There may also be more intense downpours of summer rainfall, which could lead to flash flooding.
5. The extreme heatwave of 2003, where average summer temperatures were 2 °C higher than normal, led to more than 2,000 additional deaths in the UK. Such hot summers could happen every other year by the 2040s.
6. Heavier winter precipitation is expected to become more frequent, potentially causing more flooding.
7. Sea-level across the UK is projected to rise between 11 and 76 cm by the end of the century. In the worst case, rises of up to 1.9 m are possible but highly unlikely.

Will we need to Adapt?

We all need to look at our vulnerability to the changing climate. 'Vulnerability' can be defined as being open to or at risk of damage.

Changing our behaviour to respond to the impacts of climate change is known as 'adaptation'.

Adapting to climate change is a process. That's why it needs to be built in to our normal planning and risk management processes, whether in business, government or any other sphere. That way, we can make sustainable adaptation decisions, at the right time and in order to maximise the benefits and minimise the costs.

To learn more about adaptation visit the defra web site page