IF I may sidestep the mere abuse, which does not help scientific debate, and focus on some of the genuine issues raised by your correspondents ( Climate Change is on its way , Letters, May 7). The temperature graphs? I am happy to oblige Mr Reddaway. I ag
IF I may sidestep the mere abuse, which does not help scientific debate, and focus on some of the genuine issues raised by your correspondents ("Climate Change is on its way", Letters, May 7).
The temperature graphs? I am happy to oblige Mr Reddaway. I agree that long term trends are the most useful. In my brief letter there was no space to put them all in. I merely wanted to demonstrate that the GCMs had predicted steady warming only to find that it didn't happen.
Let me clarify matters with four graphs:
Average global temperatures from 1880. This indeed does show a warming overall of about 0.6°C, the warmest decade being the 1930s and the hottest year 1934 (not 1998, pace Mr Reddaway). Temperatures fell for nearly 40 years when CO2 levels were accelerating. The main temperature hike was from 1890 to 1940. Your correspondent, Mr Maxey, conveniently started his graph when temperatures started rising in about 1972.
Before 1850 we need to rely on temperature proxies (O18 being one of the accepted yardsticks) and the next graph shows temperature fluctuations since about AD 900 (the 'hockey-stick' graph is now discredited).
Incidentally, probably the main cause of the current rise in CO2 levels comes from the delayed effect of the MWP on the oceans, which release several hundred gigatons of CO2 per degree rise in temperature. Current human input into the CO2 reservoir is about three per cent of the total.
The third graph, (based on sea surface temperatures rather than land-based temperatures), gives the general picture for the last 3,000 years, and lastly...
A temperature graph that goes back six million years and shows that we are not living in any unusual circumstances. And still no one has produced the evidence I asked for.
Mr Spencer's concern about more energy overall in the atmosphere can be relieved by understanding how the Pacific Ocean Heat Vent operates.
In 2001, it was discovered that a 'thermal iris' opens over the Pacific when the ocean surface temperatures reach about 28-30°C and huge amounts of heat are vented back out into space and dissipated - more than compensating for any 'global warming'.
Statements from the IPCC, particularly in their Summaries for Policy Makers, must be taken with a huge pinch of salt. Little of the actual science in their main report supports these conclusions. But these summaries are what are invariably read by politicians and reported by the press. And the IPCC has huge interests in promoting global alarm:
Billions of dollars ride on its promotion: carbon trading (remember ENRON?), carbon offset (which is a scandal) and 'alternative energy' and bio-fuels - which are starving the Third World. This leaves aside the huge numbers of people employed in 'climate change' research, mostly at our expense.
Incidentally, I taught sixth form chemistry and physics for several years.
Rev PHILIP FOSTER