Downlighters in celotex

[flameport]

Global warming does not mean the local climate will get warmer.
Quite the opposite is likely.

 

[Trog]

Global warming does not mean the local climate will get warmer.
Quite the opposite is likely.

In which case who burnt all the fossil fuel in the high middle ages, caused the little ice age, and froze all those poor Vikings to death?

 

[ban-all-sheds]

Something that has always worried me about global warming, is that the climate has been warmer than now in the past. For example in the early middle ages the climate in Greenland was warm enough to allow the Vikings to live by northern european subsistance agriculture, until they were wiped out when temperatures fell in the little ice age. Also the moors of Devon and Cornwall were farmland in the Bronze Age, when the climate was also warmer than now.

The climate has changed hugely in the past, and it will do so again. The fossil record shows that. And long before the Middle Ages palm trees grew in Greenland (although it was probably not in the same place).

But life evolved, and came and went - sea levels rose and fell, forests grew and died and became coal, hundreds, thousands of species of animals flourished and became extinct and became oil etc, but the Earth continued.

As it will as the climate changes again, but we won't. Our civilisation won't. Our current land masses won't. Our current weather patterns won't. Homo Sapiens won't.

You talk about the Little Ice Age - the average annual temperature of the Northern Hemisphere was only about 1°C lower than today. When the Vikings were farming in Greenland and Iceland it was about 1° warmer.

2-3° lower is real Ice Age territory, 1-2° warmer is reckoned to be "climatic optimum" (but probably not for a population of 8-10 billion people).

The do-nothing prediction for temperature rise due to global warming is 3-4° by the end of the century, or, who knows - quite possibly within the lifetime of our children.

3-4° average is huge. 3-4° will be catastrophic.

http://www.guardian.co.uk/environment/2009/sep/28/met-office-study-global-warming


3-4° hasn't been seen for 40 million years.

So who was burning all the fossil fuel in the Bronze Age, and the Dark Ages after the fall of the Roman Empire?

The fact that the current rapid increase in global warming is man made does not mean that all previous periods of warming had to be.

I don't say that there is no such thing as global warming,

That would be foolish.

and it may be caused by human emitted CO2.

"May be"?

"Expert credibility in climate change", Proceedings of the National Academy of Sciences of the United States, 2010: "the relative climate expertise and scientific prominence of the researchers unconvinced of ACC (Anthropogenic Climate Change) are substantially below that of the convinced researchers."

"Examining the Scientific Consensus on Climate Change", Transactions of the American Geophysical Union, 2009: "It seems that the debate on the authenticity of global warming and the role played by human activity is largely nonexistent among those who understand the nuances and scientific basis of long-term climate processes."

But as we are still well within the natural range of temperatures, why is it such a disaster?

Maybe that depends on whether you view a rise in sea level of 1m, the loss of drinking water for half the worlds population, massive loss of biodiversity and large swathes of the planet becoming uninhabitable as a disaster or not, I guess.

When I was at school we were being taught that we were over due for an Ice Age, now it is Global Warming. I can not help suspecting that in a few more years Global Warming will also be history.

Is that because of a deep understanding of the science, and soundly based conclusions which you could convincingly argue with other climate experts, or because you just don't want it to be true?