Dr. Patrick Moore, Greenpeace co-founder and former director Greenpeace International.
My skepticism begins with the believers' certainty they can
predict the global climate with a computer model. The entire basis
for the doomsday climate change scenario is the hypothesis increased
atmospheric carbon dioxide due to fossil fuel emissions will heat
the Earth to unlivable temperatures.
...
In fact, the Earth has been warming very gradually for 300 years,
since the Little Ice Age ended, long before heavy use of fossil
fuels. Prior to the Little Ice Age, during the Medieval Warm Period,
Vikings colonized Greenland and Newfoundland, when it was warmer
there than today. And during Roman times, it was warmer, long before
fossil fuels revolutionized civilization.
The idea it would be catastrophic if carbon dioxide were to increase
and average global temperature were to rise a few degrees is preposterous.
Clifford Asness and Aaron Brown
Of course the real but rather small trend doesn't prove that global warming
is a minor issue, far from it. We're just saying the
graph
taken on its own
is actually pretty reassuring, at least compared to predictions,
and declared danger points, of the IPCC and similar groups.
If things continue along the way they have for the last 135 years,
the point at which we reach dangerous temperatures is a very very long
time from now. Those predicting that we face a big problem much sooner
aren't arguing this from these data, instead they have to be arguing
that historical warming trends will change drastically in the near future;
that they will not continue at the trend of the past hundred years or so.
The historical record to date, and in particular this ubiquitous graph,
can't be the basis of an argument that we will hit dangerous levels soon .
To argue that we will hit them in this, or even next century requires us to
explain away this graph, to explain why the rate of warming will increase.
...
Of course, this raises the very important issue of whether or not 4°C
is the right danger line. No one knows the answer to this question,
but 4°C seems the most common figure used by the experts.
It’s what the IPCC uses in its most recent report.
No one denies that there are some risks and costs to any amount of warming,
and on the other hand, almost no one is predicting that warming at or
slightly beyond 4°C will cause extinction of the human race either.
Risks go up with the amount of warming. We just don't know how fast.
Despite the uncertainties, there seems to e a scientific consensus that
less than 1°C or 2°C of warming would make global warming no more serious
than several other environmental issues, but warming above 4°C would
likely make global warming a unique danger.
Even if the danger point is 2°C this trend doesn't reach it until over
130 years from now.
For reactions and rebuttals see Imagine if They Disagreed With Us!
What we did not expect was the immediate and strong chorus of agreement, yes agreement, from climate scientists. Equally unexpected was that their agreement would be couched in unfriendly terms!