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Climate change and energy – guidance
Climate change explained
From:Department of Energy & Climate ChangeFirst published:23 October 2014Part of:Climate change agreements, Climate change and energy, Climate change international action, + others
Climate change is happening and is due to human activity, this includes global warming and greater risk of flooding, droughts and heat waves.
Contents
Climate change now
Causes of climate change
Evidence and analysis
The effects of climate change
Agreement among experts
The role of the IPCC
Tackling climate change
UK government action
References
Climate change now
There is clear evidence to show that climate change is happening. Measurements show that the average temperature at the Earth’s surface has risen by about 0.8°C over the last century. 13 of the 14 warmest years on record have occurred in the 21st century and in the last 30 years each decade has been hotter than the previous one. This change in temperature hasn’t been the same everywhere; the increase has been greater over land than over the oceans and has been particularly fast in the Arctic.
The UK is already affected by rising temperatures. The average temperature in Britain is now 1˚C higher than it was 100 years ago and 0.5˚C higher than it was in the 1970s.
Although it is clear that the climate is warming in the long-term, note that temperatures aren’t expected to rise every single year. Natural fluctuations will still cause unusually cold years and seasons.
Along with warming at the Earth’s surface, many other changes in the climate are occurring:
warming oceans
melting polar ice and glaciers
rising sea levels
more extreme weather events
Warming oceans
While the temperature rise at the Earth’s surface may get the most headlines, the temperature of the oceans has been increasing too. This warming has been measured all the way down to 2 km deep.
The chemistry of the oceans is also changing as they absorb much of the excess carbon dioxide being emitted into the atmosphere. This is causing the oceans to become acidic more rapidly than at any point in the last 65 million years.
Melting polar ice and glaciers
As the Arctic warms, sea ice is decreasing rapidly. In the Antarctic, sea ice has slowly increased, driven by local changes in wind patterns and freshening sea water. Over the past 20 years the ice sheets (the great masses of land ice at the poles) in Greenland and the Antarctic have shrunk, as have most glaciers around the world.
Rising sea levels
As land ice melts and the warming oceans expand, sea levels have risen. Between 1901 and 2010 the global average sea level rose by 0.19 metres, likely faster than at any point in the last 2,000 years.
More extreme weather events
More damaging extreme weather events are being seen around the world. Heat waves have become more frequent and are lasting longer. The height of extreme sea levels caused by storms has increased. Warming is expected to cause more intense, heavy rainfall events. In North America and Europe, where long-term rainfall measurements exist, this change has already been observed.
Causes of climate change
Rising levels of carbon dioxide and other gases, such as methane, in the atmosphere create a ‘greenhouse effect’, trapping the Sun’s energy and causing the Earth, and in particular the oceans, to warm. Heating of the oceans accounts for over nine tenths of the trapped energy. Scientists have known about this greenhouse effect since the 19th Century.
The higher the amounts of greenhouse gases in the atmosphere, the warmer the Earth becomes. Recent climate change is happening largely as a result of this warming, with smaller contributions from natural influences like variations in the Sun’s output.
Carbon dioxide levels have increased by more than 40% since before the industrial revolution. Other greenhouse gases have increased by similarly large amounts. All the evidence shows that this increase in greenhouse gases is almost entirely due to human activity. The increase is mainly caused by:
burning of fossil fuels for energy
agriculture and deforestation
the manufacture of cement, chemicals and metals
About 43% of the carbon dioxide produced goes into the atmosphere, and the rest is absorbed by plants and the oceans. Deforestation reduces the number of trees absorbing carbon dioxide and releases the carbon contained in those trees.
Evidence and analysis
Evidence from past climate change
Ancient ice from the polar ice sheets reveal natural temperature changes over tens to hundreds of thousands of years. They show that levels of greenhouse gases in the atmosphere are closely linked to global temperatures. Rises in temperature are accompanied by an increase in the amount of greenhouse gases.
These ice cores also show that, over the last 350 years, greenhouse gases have now rapidly increased to levels not seen for at least 800,000 years and very probably longer. Modern humans, who evolved about 200,000 years ago, have never previously experienced such high levels of greenhouse gases.
Natural fluctuations in climate
Over the last million years or so the Earth’s climate has had a natural cycle of cold glacial and warm interglacial periods. This cycle is mainly driven by gradual changes in the Earth’s orbit over many thousands of years, but is amplified by changes in greenhouse gases and other influences. Climate change is always happening naturally, but greenhouse gases produced by human activity are altering this cycle.
Volcanic eruptions and changes in solar activity also affect our climate, but they alone can’t explain the changes in temperature seen over the last century.
Scientists have used sophisticated computer models to calculate how much human activity – as opposed to natural factors – is responsible for climate change. These models show a clear human ‘fingerprint’ on recent global warming.
Climate models and future global warming
We can understand a lot about the possible future effects of a warming climate by looking at changes that have already happened. But we can get much more insight by using mathematical models of the climate.
Climate models can range from a very simple set of mathematical equations (which could be solved using pen and paper) to the very complex, sophisticated models run on supercomputers (such as those at the Met Office).
While these models cannot provide very specific forecasts of what the weather will be like on a Tuesday in 100 years time, they can forecast the big changes in global climate which we could see.
All these climate models tell us that by the end of this century, without an extremely significant reduction in the amount of greenhouse gases we produce, the world is likely to become more than 3 ˚C warmer than in the 19th century. Note that this is a global average and that regional changes in some places will be even higher than this. There could even be global average rises of up to 6˚C which would have catastrophic impacts.
This means that our action – or inaction – on greenhouse gas emissions today will have a substantial effect on climate change in the future.
The effects of climate change
We can already see the impacts of climate change and these will become more severe as global temperatures rise. How great the impacts will become depends upon our success in reducing greenhouse gas emissions.
The effects of rising temperatures on the UK
If global emissions are not reduced, average summer temperatures in the south east of England are projected to rise by:
over 2˚C by the 2040s (hotter than the 2003 heatwave which was connected to 2,000 extra deaths in the UK)
up to nearly 4˚C by the 2080s
Rises in global temperature will have both direct and indirect effects on the UK. The UK’s food supplies could be affected as crops in the UK and overseas could fail or be damaged by changes in temperature, rainfall and extreme weather events.
These extreme weather events in the UK are likely to increase with rising temperatures, causing:
heavier rainfall events – with increased risk of flooding
higher sea levels – with larger storm waves putting a strain on the UK’s coastal defences
more and longer-lasting heat waves
The effect of warming on rainfall patterns and water supplies
Changing rainfall patterns will affect water supplies. Too much rainfall in some areas and not enough in others will contribute to both flood and drought conditions. We are already seeing increasing numbers of heavy rainfall events, and expect this increase to continue, with greater risk of river and flash flooding.
Mountain glaciers are expected to continue melting which, along with reduced snow cover, will put stress on communities that rely on these as sources of water.
Changes in the oceans
Increasing temperatures and acidification of the oceans are threatening sea life around the world. Coral reefs in particular will be at major risk if ocean temperatures keep increasing.
Sea levels will keep rising as the polar ice sheets and glaciers melt and the warming oceans expand. Even small increases of tens of centimetres could put thousands of lives and properties at risk from coastal flooding during stormy weather.
Coastal cities with dense populations are particularly vulnerable, especially those that can’t afford flood protection.
The impact of warming on food production
Even with low levels of warming (less than 2 ˚C above the temperature in 1800), global production of major crops such as wheat, rice and maize may be harmed. Though warming may help some crops to grow better at high latitudes, food production in low latitudes will very likely suffer. This will cause a growing gap between food demand and supply.
Because trade networks are increasingly global, the effects of extreme weather events in one part of the world will affect food supply in another. For example, floods or droughts that damage crops in Eastern Europe or the US can directly affect the cost and availab

ผลลัพธ์ (ไทย) 1:

Skip to main contentGOV.UK SearchMenuClimate change and energy – guidanceClimate change explainedFrom:Department of Energy & Climate ChangeFirst published:23 October 2014Part of:Climate change agreements, Climate change and energy, Climate change international action, + othersClimate change is happening and is due to human activity, this includes global warming and greater risk of flooding, droughts and heat waves.ContentsClimate change nowCauses of climate changeEvidence and analysisThe effects of climate changeAgreement among expertsThe role of the IPCCTackling climate changeUK government actionReferencesClimate change nowThere is clear evidence to show that climate change is happening. Measurements show that the average temperature at the Earth’s surface has risen by about 0.8°C over the last century. 13 of the 14 warmest years on record have occurred in the 21st century and in the last 30 years each decade has been hotter than the previous one. This change in temperature hasn’t been the same everywhere; the increase has been greater over land than over the oceans and has been particularly fast in the Arctic.The UK is already affected by rising temperatures. The average temperature in Britain is now 1˚C higher than it was 100 years ago and 0.5˚C higher than it was in the 1970s.Although it is clear that the climate is warming in the long-term, note that temperatures aren’t expected to rise every single year. Natural fluctuations will still cause unusually cold years and seasons.Along with warming at the Earth’s surface, many other changes in the climate are occurring:warming oceansmelting polar ice and glaciersrising sea levelsmore extreme weather eventsWarming oceansWhile the temperature rise at the Earth’s surface may get the most headlines, the temperature of the oceans has been increasing too. This warming has been measured all the way down to 2 km deep.The chemistry of the oceans is also changing as they absorb much of the excess carbon dioxide being emitted into the atmosphere. This is causing the oceans to become acidic more rapidly than at any point in the last 65 million years.Melting polar ice and glaciersAs the Arctic warms, sea ice is decreasing rapidly. In the Antarctic, sea ice has slowly increased, driven by local changes in wind patterns and freshening sea water. Over the past 20 years the ice sheets (the great masses of land ice at the poles) in Greenland and the Antarctic have shrunk, as have most glaciers around the world.Rising sea levelsAs land ice melts and the warming oceans expand, sea levels have risen. Between 1901 and 2010 the global average sea level rose by 0.19 metres, likely faster than at any point in the last 2,000 years.More extreme weather eventsเพิ่มเติมเสียหายเหตุการณ์สภาพอากาศมากจะมีเห็นทั่วโลก คลื่นความร้อนเป็นบ่อยขึ้น และยาวนานอีกต่อไป มีเพิ่มความสูงของระดับน้ำทะเลมากที่เกิดจากพายุ ภาวะโลกร้อนคาดว่าจะเกิดเหตุการณ์ฝนตกหนัก รุนแรงมากขึ้น ในอเมริกาเหนือและยุโรป ที่วัดปริมาณน้ำฝนระยะยาวมี การเปลี่ยนแปลงนี้มีแล้วถูกตรวจสอบสาเหตุของการเปลี่ยนแปลงสภาพภูมิอากาศเพิ่มขึ้นระดับของก๊าซคาร์บอนไดออกไซด์และก๊าซอื่น ๆ เช่นมีเทน ในบรรยากาศสร้างความ 'เรือนกระจก' ดักจับพลังงานจากแสงอาทิตย์ และก่อให้เกิดโลก และโดยเฉพาะอย่างยิ่งในมหาสมุทร อุ่น ความร้อนของบัญชีของมหาสมุทรกว่าเก้าหนึ่งตำแหน่งพลังงานติดอยู่ นักวิทยาศาสตร์ได้ทราบเกี่ยวกับเรือนกระจกนี้ตั้งแต่ศตวรรษที่ 19ยิ่งจำนวนของก๊าซเรือนกระจกในชั้นบรรยากาศ โลกที่อุ่นกลายเป็น เปลี่ยนแปลงสภาพภูมิอากาศล่าสุดเกิดขึ้นเนื่องจากการนี้ร้อน มีผลงานขนาดเล็กจากอิทธิพลธรรมชาติเช่นในการแสดงผลของดวงอาทิตย์ระดับก๊าซคาร์บอนไดออกไซด์ได้เพิ่มขึ้นมากกว่า 40% ตั้งแต่ก่อนการปฏิวัติอุตสาหกรรม ก๊าซเรือนกระจกอื่น ๆ ได้เพิ่มขึ้นในทำนองเดียวกันจำนวนมาก หลักฐานทั้งหมดแสดงว่า ก๊าซเรือนกระจกนี้เพิ่มเป็นเกือบทั้งหมดเนื่องจากกิจกรรมของมนุษย์ การเพิ่มขึ้นส่วนใหญ่เกิดจาก:เผาไหม้ของเชื้อเพลิงฟอสซิลพลังงานการเกษตรและการตัดไม้ทำลายป่าการผลิตปูนซีเมนต์ เคมีภัณฑ์ และโลหะAbout 43% of the carbon dioxide produced goes into the atmosphere, and the rest is absorbed by plants and the oceans. Deforestation reduces the number of trees absorbing carbon dioxide and releases the carbon contained in those trees.Evidence and analysisEvidence from past climate changeAncient ice from the polar ice sheets reveal natural temperature changes over tens to hundreds of thousands of years. They show that levels of greenhouse gases in the atmosphere are closely linked to global temperatures. Rises in temperature are accompanied by an increase in the amount of greenhouse gases.These ice cores also show that, over the last 350 years, greenhouse gases have now rapidly increased to levels not seen for at least 800,000 years and very probably longer. Modern humans, who evolved about 200,000 years ago, have never previously experienced such high levels of greenhouse gases.Natural fluctuations in climateOver the last million years or so the Earth’s climate has had a natural cycle of cold glacial and warm interglacial periods. This cycle is mainly driven by gradual changes in the Earth’s orbit over many thousands of years, but is amplified by changes in greenhouse gases and other influences. Climate change is always happening naturally, but greenhouse gases produced by human activity are altering this cycle.Volcanic eruptions and changes in solar activity also affect our climate, but they alone can’t explain the changes in temperature seen over the last century.Scientists have used sophisticated computer models to calculate how much human activity – as opposed to natural factors – is responsible for climate change. These models show a clear human ‘fingerprint’ on recent global warming.Climate models and future global warmingWe can understand a lot about the possible future effects of a warming climate by looking at changes that have already happened. But we can get much more insight by using mathematical models of the climate.Climate models can range from a very simple set of mathematical equations (which could be solved using pen and paper) to the very complex, sophisticated models run on supercomputers (such as those at the Met Office).While these models cannot provide very specific forecasts of what the weather will be like on a Tuesday in 100 years time, they can forecast the big changes in global climate which we could see.All these climate models tell us that by the end of this century, without an extremely significant reduction in the amount of greenhouse gases we produce, the world is likely to become more than 3 ˚C warmer than in the 19th century. Note that this is a global average and that regional changes in some places will be even higher than this. There could even be global average rises of up to 6˚C which would have catastrophic impacts.This means that our action – or inaction – on greenhouse gas emissions today will have a substantial effect on climate change in the future.The effects of climate change
We can already see the impacts of climate change and these will become more severe as global temperatures rise. How great the impacts will become depends upon our success in reducing greenhouse gas emissions.
The effects of rising temperatures on the UK
If global emissions are not reduced, average summer temperatures in the south east of England are projected to rise by:
over 2˚C by the 2040s (hotter than the 2003 heatwave which was connected to 2,000 extra deaths in the UK)
up to nearly 4˚C by the 2080s
Rises in global temperature will have both direct and indirect effects on the UK. The UK’s food supplies could be affected as crops in the UK and overseas could fail or be damaged by changes in temperature, rainfall and extreme weather events.
These extreme weather events in the UK are likely to increase with rising temperatures, causing:
heavier rainfall events – with increased risk of flooding
higher sea levels – with larger storm waves putting a strain on the UK’s coastal defences
more and longer-lasting heat waves
The effect of warming on rainfall patterns and water supplies
Changing rainfall patterns will affect water supplies. Too much rainfall in some areas and not enough in others will contribute to both flood and drought conditions. We are already seeing increasing numbers of heavy rainfall events, and expect this increase to continue, with greater risk of river and flash flooding.
Mountain glaciers are expected to continue melting which, along with reduced snow cover, will put stress on communities that rely on these as sources of water.
Changes in the oceans
Increasing temperatures and acidification of the oceans are threatening sea life around the world. Coral reefs in particular will be at major risk if ocean temperatures keep increasing.
Sea levels will keep rising as the polar ice sheets and glaciers melt and the warming oceans expand. Even small increases of tens of centimetres could put thousands of lives and properties at risk from coastal flooding during stormy weather.
Coastal cities with dense populations are particularly vulnerable, especially those that can’t afford flood protection.
The impact of warming on food production
Even with low levels of warming (less than 2 ˚C above the temperature in 1800), global production of major crops such as wheat, rice and maize may be harmed. Though warming may help some crops to grow better at high latitudes, food production in low latitudes will very likely suffer. This will cause a growing gap between food demand and supply.
Because trade networks are increasingly global, the effects of extreme weather events in one part of the world will affect food supply in another. For example, floods or droughts that damage crops in Eastern Europe or the US can directly affect the cost and availab

ผลลัพธ์ (ไทย) 3:

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