You Decide

Plant trees which give off oxygen as a by-product of their growth aside from being aesthetically pleasing.  Then by the time the cycle changes back to global warming there will be more shade, preventing heat from absorbing into the surface.

Wonder how global warming scientists would do on "Are You Smarter Than a Fifth Grader"?

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"What happened to global warming?

By Paul Hudson
Climate correspondent, BBC News

"This headline may come as a bit of a surprise, so too might that factthat the warmest year recorded globally was not in 2008 or 2007, but in1998.

But it is true. For the last 11 years we have not observed any increase in global temperatures.

And our climate models did not forecast it, even though man-made carbondioxide, the gas thought to be responsible for warming our planet, hascontinued to rise.

So what on Earth is going on?

Climate change sceptics, who passionately and consistently argue thatman's influence on our climate is overstated, say they saw it coming.

They argue that there are natural cycles, over which wehave no control, that dictate how warm the planet is. But what is theevidence for this?

During the last few decades of the 20th Century, our planet did warm quickly.

Sceptics argue that the warming we observed was down to the energy fromthe Sun increasing. After all 98% of the Earth's warmth comes from theSun.

But research conducted two years ago, and published by the Royal Society, seemed to rule out solar influences.

The scientists' main approach was simple: to look at solar output andcosmic ray intensity over the last 30-40 years, and compare thosetrends with the graph for global average surface temperature.

And the results were clear. "Warming in the last 20 to40 years can't have been caused by solar activity," said Dr PiersForster from Leeds University, a leading contributor to this year'sIntergovernmental Panel on Climate Change (IPCC).

But one solar scientist Piers Corbyn fromWeatheraction, a company specialising in long range weatherforecasting, disagrees.

He claims that solar charged particles impact us farmore than is currently accepted, so much so he says that they arealmost entirely responsible for what happens to global temperatures.

He is so excited by what he has discovered that heplans to tell the international scientific community at a conference inLondon at the end of the month.

If proved correct, this could revolutionise the whole subject.

Ocean cycles

What is really interesting at the moment is what is happening to our oceans. They are the Earth's great heat stores.

“ In the last few years [the Pacific Ocean] has been losing its warmth and has recently started to cool down ”

According to research conducted by Professor Don Easterbrook fromWestern Washington University last November, the oceans and globaltemperatures are correlated.

The oceans, he says, have a cycle in which they warmand cool cyclically. The most important one is the Pacific decadaloscillation (PDO).

For much of the 1980s and 1990s, it was in a positivecycle, that means warmer than average. And observations have revealedthat global temperatures were warm too.

But in the last few years it has been losing its warmth and has recently started to cool down.

These cycles in the past have lasted for nearly 30 years.

So could global temperatures follow? The global cooling from 1945 to1977 coincided with one of these cold Pacific cycles.

Professor Easterbrook says: "The PDO cool mode hasreplaced the warm mode in the Pacific Ocean, virtually assuring us ofabout 30 years of global cooling."

So what does it all mean? Climate change sceptics argue that this is evidence that they have been right all along.

They say there are so many other natural causes for warming andcooling, that even if man is warming the planet, it is a small partcompared with nature.

But those scientists who are equally passionate aboutman's influence on global warming argue that their science is solid.

The UK Met Office's Hadley Centre, responsible forfuture climate predictions, says it incorporates solar variation andocean cycles into its climate models, and that they are nothing new.

In fact, the centre says they are just two of the wholehost of known factors that influence global temperatures - all of whichare accounted for by its models.

In addition, say Met Office scientists, temperatureshave never increased in a straight line, and there will always beperiods of slower warming, or even temporary cooling.

What is crucial, they say, is the long-term trend inglobal temperatures. And that, according to the Met office data, isclearly up.

To confuse the issue even further, last month MojibLatif, a member of the IPCC (Intergovernmental Panel on Climate Change)says that we may indeed be in a period of cooling worldwidetemperatures that could last another 10-20 years.

Professor Latif is based at the Leibniz Institute of Marine Sciences atKiel University in Germany and is one of the world's top climatemodellers.

But he makes it clear that he has not become a sceptic;he believes that this cooling will be temporary, before theoverwhelming force of man-made global warming reasserts itself.

So what can we expect in the next few years?

Both sides have very different forecasts. The Met Office says that warming is set to resume quickly and strongly.

It predicts that from 2010 to 2015 at least half the years will be hotter than the current hottest year on record (1998).

Sceptics disagree. They insist it is unlikely that temperatures willreach the dizzy heights of 1998 until 2030 at the earliest. It ispossible, they say, that because of ocean and solar cycles a period ofglobal cooling is more likely.

One thing is for sure. It seems the debate about whatis causing global warming is far from over. Indeed some would say it ishotting up."

Story from BBC NEWS:
http://news.bbc.co.uk/go/pr/fr/-/2/hi/science/nature/8299079.stm

Published: 2009/10/09 15:22:46 GMT

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