No disputing reality of global warming
In a recent letter, Donn Dears disputes global warming on the grounds that British Met Office data show no such warming. However, this conclusion was made by the London Daily Mail, an article the Met Office called "misleading."
The Met Office pointed out that over relatively short periods of time, natural climate variations could show either warming or cooling, but that the long-term trend clearly showed that global warming was a fact. The Daily Mail article cherry-picked a short-term trend in the data to arrive at its conclusion.
That global warming is real should not come as a surprise. The surprise would be if there was not any warming. Burning of fossil fuels, such as coal, oil, and natural gas, inevitably produces carbon dioxide gas which is released into the atmosphere. The concentration of CO2 in the atmosphere is easily measured, and it is increasing. CO2 has the property that, put simply, it is transparent to short-wave heat radiation from the sun, but relatively opaque to long-wave radiation from the earth. Glass has a similar property, which is why a greenhouse works. Therefore, as CO2 increases in the atmosphere, we would expect the temperature at the earth's surface to go up. If we look at the Met Office data over a longer time period than the Daily Mail used, that is exactly what we see.
The bigger question is what effect this global warming trend has on local climate. Some areas will undoubtedly get warmer, but others could get cooler. Either way, the effect of climate change on such things as agriculture, livestock population, waterway transport, health and storm damage could be immense. This is why we need to not only recognize the reality of global warming but do all we can to decrease our reliance on the fossil fuels that cause it.