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Q1: Because of the way that 'greenhouse' gasses interact with the wavelengths of light to trap infrared radiation as it is radiated back from the Earth, are there any gasses that can radiate the infrared light before it reaches the ground? A kind of negative methane and carbon dioxide.?
Q2: What do you think the likely effects on global warming will be if we take out the global dimming factor by reducing the amount of dust particles and pollution that we are putting into the atmosphere?
Q3: How can this subject be taken seriously when there are so many conflicting views? Only recently (3 months ago) 41 scientists signed off on a letter disputing the findings or pronouncements of the British scientists and have advised the Canadian Prime Minister of the exact opposite namely that global warming is all just natural "noise" and within perfectly normal shifting weather patterns dating back thousands of years. Who's right, who's wrong?
Q2: What do you think the likely effects on global warming will be if we take out the global dimming factor by reducing the amount of dust particles and pollution that we are putting into the atmosphere?
Q3: How can this subject be taken seriously when there are so many conflicting views? Only recently (3 months ago) 41 scientists signed off on a letter disputing the findings or pronouncements of the British scientists and have advised the Canadian Prime Minister of the exact opposite namely that global warming is all just natural "noise" and within perfectly normal shifting weather patterns dating back thousands of years. Who's right, who's wrong?
Q5: If parts of the United Kingdom were to become submerged due to global warming, what would the UK look like?
JR, Derbyshire
Dr New: Future sea level rise is quite difficult to estimate accurately, as it depends on several factors:
heat expansion of the ocean, melting of mountain glaciers melting of the Greenland and Antarctic ice sheets and the way these large scale changes interact with local coastal geometry.
Estimates of changes in global sea level since 1900 range from about 1cm to 20cm; by 2020 sea levels should rise a further 5-20cm and by the end of the century they might have risen by up to one metre compared to today, with a best estimate of about half a metre.
One thing is for sure, the rate of increase will accelerate over the next 100 years. This is because ice sheets, glaciers and oceans are still adjusting to the past warming of the atmosphere, and will also respond to the accelerating future warming.
A big uncertainty is the stability of the Greenland (and perhaps the Antarctic) ice sheet. Some scientists estimate that sometime in the next 40 years temperatures over Greenland will have risen enough to cause irreversible melting; even if temperatures were to decrease again further in the future, the Greenland ice sheet would continue to gradually melt, causing a 7m rise in sea level over 1000-2000 years.
To see what the UK would look like for several extreme changes in sea level, visit the Benfield Hazard Research Centre.
For a city like London, the timing of a "Thames overflow" is uncertain, as it depends not only on the rate of sea level rise but also the occurrence of a large tidal storm surge up the estuary, perhaps coupled with a large flood from the Thames catchment. Any rise in sea level will increase the risk of an overflow. There are plans to upgrade the Thames Barrier and other London flood defence systems so that London is protected at least until 2100. A rise of 7m over the longer term would require defences such as those currently in place in the Netherlands, perhaps coupled with abandonment of less valuable areas.
JR, Derbyshire
Dr New: Future sea level rise is quite difficult to estimate accurately, as it depends on several factors:
Estimates of changes in global sea level since 1900 range from about 1cm to 20cm; by 2020 sea levels should rise a further 5-20cm and by the end of the century they might have risen by up to one metre compared to today, with a best estimate of about half a metre.
One thing is for sure, the rate of increase will accelerate over the next 100 years. This is because ice sheets, glaciers and oceans are still adjusting to the past warming of the atmosphere, and will also respond to the accelerating future warming.
A big uncertainty is the stability of the Greenland (and perhaps the Antarctic) ice sheet. Some scientists estimate that sometime in the next 40 years temperatures over Greenland will have risen enough to cause irreversible melting; even if temperatures were to decrease again further in the future, the Greenland ice sheet would continue to gradually melt, causing a 7m rise in sea level over 1000-2000 years.
To see what the UK would look like for several extreme changes in sea level, visit the Benfield Hazard Research Centre.
For a city like London, the timing of a "Thames overflow" is uncertain, as it depends not only on the rate of sea level rise but also the occurrence of a large tidal storm surge up the estuary, perhaps coupled with a large flood from the Thames catchment. Any rise in sea level will increase the risk of an overflow. There are plans to upgrade the Thames Barrier and other London flood defence systems so that London is protected at least until 2100. A rise of 7m over the longer term would require defences such as those currently in place in the Netherlands, perhaps coupled with abandonment of less valuable areas.
