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Is global warming a bigger threat than terrorism?
Climate change poses a bigger threat to the planet than terrorism - so says the UK government's
chief scientific adviser, Sir David King
Is global warming a bigger threat than terrorism?
but in the US a leading politician calls it:
"possibly the greatest hoax ever perpetrated on the American people"
VIDEO CLIPS
• Melting Polar Ice Caps
• Global Warning?
Q&A: Climate change • Accelerating ice-melt may be a sign
of global climate change• The Earth is getting warmer.
Scientists predict increasing droughts, floods and extreme weather and say there is growing evidence that human activities are to blame.
• BBC News Online looks at the key questions behind climate change and global warming.
http://news.bbc.co.uk/1/hi/sci/tech/3928017.stm
Global climate changeand
paleoclimate change
What evidence do we have?
• What is climate change? • The planet's climate is constantly changing. The
global average temperature is currently in the region of 15C. Geological and other evidence suggests that, in the past, this average may have been as high as 27C and as low as 7C.
• But scientists are concerned that the natural fluctuation has been overtaken by a rapid human-induced warming that has serious implications for the stability of the climate on which much life on the planet depends.
http://news.bbc.co.uk/nol/shared/spl/hi/pop_ups/04/sci_nat_enl_1092666337/img/1.jpg
• What is the evidence of warming? • Temperature records go back to the late 19th Century
and show that global average temperature increased by about 0.6C in the 20th Century.
• Sea levels have risen 10 - 20cm - thought to be due mainly to the expansion of warming oceans.
• Most of the recorded non-polar glaciers are in retreat and records show Arctic sea-ice has thinned by 40% in recent decades in summer and autumn.
• There are anomalies however - parts of the Antarctic appear to be getting colder, and there are discrepancies between trends in surface temperatures and those in the troposphere.
The world heated up by about 0.6 degrees last century, and the 1990s were the warmest decade on record,
the International Panel on Climate Change (IPCC) says.
Warming world
Scientists say average global temperatures have varied by less than one degree since the dawn of human civilisation, although they fluctuated much more before that. The
IPCC predicts a global rise of between 1.4C and 5.8C by the year 2100.
Long-term high
Rising temperatures are thought to cause sea levels to rise as the oceans expand and polar ice melts. The IPCC says sea levels rose between 10 and 20cm worldwide
during the 20th Century. It predicts a further rise of between 9cm and 88cm by 2100.
Sea level rise
Thinning ice
According to the IPCC, North Pole sea-ice has thinned by 40% in recent decades in summer and autumn.
Global snow cover has shrunk by 10% since the 1960s and mountain glaciers have also retreated.
• What is the "greenhouse effect"? • The "greenhouse effect" refers to the role played by a
layer of gases which effectively trap the heat from the Sun in the Earth's atmosphere. Without them, the planet would be too cold to sustain life as we know it.
• These gases include carbon dioxide, methane and nitrous oxide, which are released by modern industry, agriculture and the burning of fossil fuels.
• Their concentration in the atmosphere is increasing - the concentration of carbon dioxide has risen by more than 30% since 1800.
• The majority of scientists accept the theory that an increase in these gases will cause a rise in the Earth's temperature.
Growing emissions
Most mainstream scientists believe that increased emissions of greenhouse cases, particularly carbon dioxide, are contributing to the warming of the
planet. This graph shows how carbon dioxide levels have increased as the world has industrialised.
• How much will temperatures rise? • If nothing is done to reduce emissions, current climate models
predict a global temperature increase of 1.4 - 5.8°C by 2100. • To put this in context, global temperatures are thought to have
fluctuated by only one degree Celsius since the dawn of human civilisation.
• Even if we cut greenhouse gas emissions dramatically now, scientists say the effects would continue because parts of the climate system, particularly large bodies of water and ice, can take hundreds of years to respond to changes in temperature.
• Some scientists say it is possible that we have already irrevocably committed the Greenland ice sheet to melting.
• This would take centuries - if not millennia - but would cause an estimated seven metre rise in sea level.
Warmer future
This map, from the UK’s Hadley Centre, assumes that current emissions trends continue, with moderate economic growth and few measures to reduce emissions. It predicts the greatest rises in northern polar regions, India, Africa
and parts of South America.
GLOBAL WARMING: Early Warning GLOBAL WARMING: Early Warning SignsSigns
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Fingerprints and HarbingersHeat waves and periods of unusually warm weather
Sea level rise and coastal flooding
Glaciers melting
Arctic and Antarctic warming
Spreading disease
Earlier spring arrival
Plant and animal range shifts and population declines
Coral reef bleaching
Downpours, heavy snowfalls, and flooding
Droughts and fires
What is global warming?
• What is it?
• Environmental Protection Agency definition
• How will the weather change? • Globally, we can expect more extreme weather events,
with heat waves becoming hotter and more frequent. • Scientists predict more rainfall overall, but say the risk of
drought in inland areas during hot summers will increase. • More flooding is expected from storms and rising sea
levels. • There are, however, likely to be very strong regional
variations in these patterns, and these are difficult to predict.
• What will the effects be? • The potential impact is huge, with predicted freshwater
shortages, sweeping changes in food production conditions, and increases in deaths from floods, storms, heat waves and droughts.
• Poorer countries, which are least equipped to deal with rapid change, will suffer most.
• Plant and animal extinctions are predicted as habitats change faster than species can adapt, and the World Health Organisation has warned that the health of millions could be threatened by increases in malaria, water-borne disease and malnutrition.
• What don't we know? • We don't know exactly how much warming is caused by
human activities or what the knock-on effects of the warming will be.
• Global warming will cause some changes which will speed up further warming, such as the release of large quantities of the greenhouse gas methane as permafrost melts.
• Other factors may mitigate warming - such as plants taking more CO2 from the atmosphere as their growth rate is increased by warmer conditions.
• Scientists are sure how the complex balance between these positive and negative feedback effects will play out.
• What about the sceptics? • Most global warming sceptics do not deny that the world
is getting warmer, but they do doubt that human activity is the cause.
• Some say the changes now being witnessed are not extraordinary - similar, rapid changes can be seen at other times in Earth's history when humans did not exist.
• Some point to the Sun's present high activity as the prime influence on recent temperature trends.
• Nevertheless, there is a growing scientific consensus that, even on top of the natural variability of the climate, something out of the ordinary is happening and humans are to blame.
• What is the international community doing? • An international agreement, the Kyoto Protocol, commits
industrialised countries to specific targets for reducing their greenhouse gas emissions.
• It must be ratified by a certain number of countries before it becomes binding. The protocol suffered a huge blow when the US - responsible for a quarter of global emissions - pulled out in 2001.
• The agreement will now only come into force if Russia ratifies it.
• While many countries have taken steps to reduce their emissions, the Kyoto targets are just a fraction of the emissions reductions thought necessary to slow global warming significantly.
Is the climate changing?The UK is warmer now than any time in the past 200 years; global temperatures have risen 0.6°C
Global climate change isn't a recent phenomenon - the Earth's climate undergoes cycles of ice ages and warm periods
October 2001 was the warmest October since records began in 1659, and summer 2003 was Europe's hottest for 500 years
Temperature measurements before the 1960s are patchy, and some scientists dispute the significance of current measurements
Computer simulations suggest that by 2050 parts of southeast England could be under water
Temperature measurements before the 1960s are patchy, and some scientists dispute the significance of current measurements
Changes in global climate are affecting animal behaviour. In the UK, birds are laying eggs early and inhabiting more northerly areas
Animal behaviour is affected by many things, such as competition between species, so these events may not be due to climate change
A UK team of scientists says less radiation is escaping into space than before, so the greenhouse effect has definitely increased
Recent theories suggest that the Sun could play a larger role than greenhouse gas emissions in global warming
• History of Global Warming
NOW with Bill Moyers
• Debating Global Warming
NOW with Bill Moyers
Skeptical of global warming fears: In favor of a global effort to reverse climate change:
"Environmentalists have viewed climate change as a catastrophe necessitating immediate and major steps to head off or mitigate. Whether global warming will occur is uncertain. Although temperature data until now could reflect a warming planet, they are also consistent with normal fluctuations in weather. From a scientific viewpoint the evidence for global warming must be 'not proven.'" - Thomas Gale Moore, Hoover Institute
"Even if the theory of global warming is wrong, we will be doing the right thing — in terms of economic policy and environmental policy." - Tim Wirth, former U.S. Senator from Colorado
Source: http://www.pbs.org/now/science/climatedebate.html
Skeptical of global warming fears: In favor of a global effort to reverse climate change:
"I believe that it is fair to say that the people once labeled as 'a small band of skeptics' — those who championed the position that warming would be modest and primarily in the coldest air-masses have won the day. Many of these same scientists are now forming a new environmental paradigm. It is that the concept of 'fragile earth' must be abandoned. And it asks the impertinent question: since when is everything that man does to the planet necessarily bad?" - Patrick J. Michaels, CATO Institute Congressional Testimony
"In the United States…we have to first convince the American people and the Congress that the climate problem is real." - former President Bill Clinton, 1997 address to the United Nations
Source: http://www.pbs.org/now/science/climatedebate.html
Skeptical of global warming fears: In favor of a global effort to reverse climate change:
"Scientists who want to attract attention to themselves, who want to attract great funding to themselves, have to (find a) way to scare the public…and this you can achieve only by making things bigger and more dangerous than they really are." - Petr Chylek, Professor of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia
"People are changing the climate that made life on earth possible and the results are disastrous - extreme weather events, such as droughts and floods, disruption of water supplies, melting Polar regions, rising sea levels, loss of coral reefs and much more. It is not too late to slow global warming and avoid the climate catastrophe that scientists predict. The solutions already exist. Renewable energy sources such as wind and solar offer abundant clean energy that is safe for the environment and good for the economy." - Greenpeace
Source: http://www.pbs.org/now/science/climatedebate.html
Skeptical of global warming fears: In favor of a global effort to reverse climate change:
"The Little Ice Age and the Medieval Warming that preceded it from 950 to 1300 AD stand out in every temperature record as the major weather events of the last 1,000 years, and they're a hefty problem for global warming advocates. If the world was warmer in 1200 AD than today, and far colder in the year 1400, why would we blame current temperatures trends on auto exhausts?" - Dennis Avery, Center for Global Food Issues
"Emissions of greenhouse gases and aerosols due to human activities continue to alter the atmosphere in ways that are expected to affect the climate." - Summary for Policymakers, A Report of Working Group 1 of the Intergovernmental Panel on Climate Change
Source: http://www.pbs.org/now/science/climatedebate.html
BBC Guide to Climate Change
• Global Warning?
• Climate Forecast
• Greenhouse Effect – simple animation
• The carbon cycle
• Feedback effects
• Gulf Stream
• How environment-savvy are you?
Items relating to the politics and debate of global warming
• BBC Global warning? program
CLIMATE WARS
Programme 1: The scienceTwo Harvard astronomers became the toast of Washington as they attacked the consensus view that global warming
is a problem, and argued that humanity has survived similar episodes as recently as the Middle Ages.
Gerry Northam charts the genesis and fate of this research, how it has been taken up by Washington conservatives, and the highly enflamed
debate that followed.
CLIMATE WARS
Programme 2: The action
The Kyoto protocol was meant to be the first step towards stopping and reversing global warming, but when the US declared it would have nothing to do with it in 2001, the treaty looked dead. That's
what the US administration argued at the time.
But with Russia perhaps on the brink of signing the protocol, despite a fog of words suggesting the opposite, and with the rest of the
industrialised world and even individual states in the USA moving ahead with climate measures, it may be that Washington gets left
behind.
• The Kyoto Agreement BBC site
Skeptical of global warming fears: In favor of a global effort to reverse climate change:
"Environmentalists have viewed climate change as a catastrophe necessitating immediate and major steps to head off or mitigate. Whether global warming will occur is uncertain. Although temperature data until now could reflect a warming planet, they are also consistent with normal fluctuations in weather. From a scientific viewpoint the evidence for global warming must be 'not proven.'" - Thomas Gale Moore, Hoover Institute
"Even if the theory of global warming is wrong, we will be doing the right thing — in terms of economic policy and environmental policy." - Tim Wirth, former U.S. Senator from Colorado
"I believe that it is fair to say that the people once labeled as 'a small band of skeptics' — those who championed the position that warming would be modest and primarily in the coldest air-masses have won the day. Many of these same scientists are now forming a new environmental paradigm. It is that the concept of 'fragile earth' must be abandoned. And it asks the impertinent question: since when is everything that man does to the planet necessarily bad?" - Patrick J. Michaels, CATO Institute Congressional Testimony
"In the United States…we have to first convince the American people and the Congress that the climate problem is real." - former President Bill Clinton, 1997 address to the United Nations
"Scientists who want to attract attention to themselves, who want to attract great funding to themselves, have to (find a) way to scare the public…and this you can achieve only by making things bigger and more dangerous than they really are." - Petr Chylek, Professor of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia
"People are changing the climate that made life on earth possible and the results are disastrous - extreme weather events, such as droughts and floods, disruption of water supplies, melting Polar regions, rising sea levels, loss of coral reefs and much more. It is not too late to slow global warming and avoid the climate catastrophe that scientists predict. The solutions already exist. Renewable energy sources such as wind and solar offer abundant clean energy that is safe for the environment and good for the economy." - Greenpeace
"The Little Ice Age and the Medieval Warming that preceded it from 950 to 1300 AD stand out in every temperature record as the major weather events of the last 1,000 years, and they're a hefty problem for global warming advocates. If the world was warmer in 1200 AD than today, and far colder in the year 1400, why would we blame current temperatures trends on auto exhausts?" - Dennis Avery, Center for Global Food Issues
"Emissions of greenhouse gases and aerosols due to human activities continue to alter the atmosphere in ways that are expected to affect the climate." - Summary for Policymakers, A Report of Working Group 1 of the Intergovernmental Panel on Climate Change
Extreme Weather
• Increasing temperatures means the World is likely to see less frosty days and cold spells, but we are expected to experience an increase in heat waves and hot spells
• Greater risk of drought in summer in continental areas • The greatest warming over the next 100 years is expected to be at higher
latitudes and the smallest amount of warming, in the tropics • Increase in extreme precipitation events • Hurricanes likely to be more intense in some parts of the World due to
more rainfall and more intense winds • It’s not clear what will happen with thunderstorms or tornadoes • An intensification of the Asian summer monsoon is expected • There is no evidence for changes in the frequency, intensity or location of
tropical storms • Storm surges are expected to increase in frequency and in the UK the
south east coast is expected to see the largest surges at around 1.2m higher than we have now (this is in the 2080’s with the "medium high emissions" scenario)
Global climate changeis characterized by changes in
climate on a regional and global scale such that many regions
experience change in climate as opposed to localized climate
change
Geologic change refers to the immense time that the earth has
existed and through which change has occurred.
These may be rapid changes, or slow, gradual changes
Geologic change can occur as the result of a meteorite impact one
Tuesday afternoon, or as mountains form as continents
collide of tens of millions of years.Both have the potential to affect
global climate
Global climate change todayAKA global warming
Q: Is Climate Change and Global Warming a real threat to the United Kingdom in your opinion? (John Gearing, St Helens)
A: I think that it is a very great threat - I always say it is the ultimate weapon of mass destruction. There's nothing we can do about Global Warming.
We're locked into a scenario of ever increasing climate change.
http://www.bbc.co.uk/weather/bbcweather/forecasters/michael_fish_question.shtml
Ask Michael Fish – questions on his retirement as BBC Weatherman for 30 years:
