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Showing posts with label GlobalWarming. Show all posts
Showing posts with label GlobalWarming. Show all posts
Temperatures 2,000 years ago about 1 deg C warmer than now

Temperatures 2,000 years ago about 1 deg C warmer than now

Well done article in the UK Daily Mail. Where is the coverage in the US about this? Note the importance of the sun in the changing temperatures.
How did the Romans grow grapes in northern England? Perhaps because it was warmer than we thought.

A study suggests the Britain of 2,000 years ago experienced a lengthy period of hotter summers than today.

German researchers used data from tree rings – a key indicator of past climate – to claim the world has been on a ‘long-term cooling trend’ for two millennia until the global warming of the twentieth century.

This cooling was punctuated by a couple of warm spells.

These are the Medieval Warm Period, which is well known, but also a period during the toga-wearing Roman times when temperatures were apparently 1 deg C warmer than now.

They say the very warm period during the years 21 to 50AD has been underestimated by climate scientists.

Lead author Professor Dr Jan Esper of Johannes Gutenberg University in Mainz said: ‘We found that previous estimates of historical temperatures during the Roman era and the Middle Ages were too low.

‘This figure we calculated may not seem particularly significant, however it is not negligible when compared to global warming, which up to now has been less than 1 deg C.’

In general the scientists found a slow cooling of 0.6C over 2,000 years, which they attributed to changes in the Earth’s orbit which took it further away from the Sun. . . .

The UK Guardian has the resource available here.  The three top countries in terms of emissions in order are China, US, and India.
Yet, how their emission levels per capita have change over time is pretty startling.  As far as I can tell, the US emissions per capita appears to have fallen the largest absolute amount, though it is still higher than a lot of other countries.  Personally, CO2 output doesn't concern me (see these links here).


Godfather of Global Warming sets environmentalists straight

Godfather of Global Warming sets environmentalists straight

SO much for the oft repeated claim of consensus on man-made Global warming being a real threat.  You have to read the Toronto Sun piece to see his discussion taking on the claim that "the science is settled."

Two months ago, James Lovelock, the godfather of global warming, gave a startling interview to msnbc.com in which he acknowledged he had been unduly “alarmist” about climate change. . . .
Lovelock is a world-renowned scientist and environmentalist whose Gaia theory — that the Earth operates as a single, living organism — has had a profound impact on the development of global warming theory. . . .
Having observed that global temperatures since the turn of the millennium have not gone up in the way computer-based climate models predicted, Lovelock acknowledged, “the problem is we don’t know what the climate is doing. We thought we knew 20 years ago.” Now, Lovelock has given a follow-up interview to the UK’s Guardian newspaper in which he delivers more bombshells sure to anger the global green movement, which for years worshipped his Gaia theory and apocalyptic predictions that billions would die from man-made climate change by the end of this century.
Lovelock still believes anthropogenic global warming is occurring and that mankind must lower its greenhouse gas emissions, but says it’s now clear the doomsday predictions, including his own (and Al Gore’s) were incorrect. . . .
“It just so happens that the green religion is now taking over from the Christian religion,” Lovelock observed. “I don’t think people have noticed that, but it’s got all the sort of terms that religions use … The greens use guilt. That just shows how religious greens are. You can’t win people round by saying they are guilty for putting (carbon dioxide) in the air.” . . .
“so-called ‘sustainable development’ … is meaningless drivel … We rushed into renewable energy without any thought. The schemes are largely hopelessly inefficient and unpleasant. I personally can’t stand windmills at any price.” . . .
So if geoengineering works, how much does that reduce any claimed externality from carbon emissions?

So if geoengineering works, how much does that reduce any claimed externality from carbon emissions?

Reducing the direct sunlight reaching the ground by 20 percent seems like a pretty large effect to me.  Will the claimed necessity of a carbon tax be adjusted for this possibility?  Personally, I think that warmer weather on net produces more good than bad.  From New Scientist:

Blue skies would fade to hazy white if geoengineers inject light-scattering aerosols into the upper atmosphere to offset global warming. Critics have already warned that this might happen, but now the effect has been quantified.
Releasing sulphate aerosols high in the atmosphere should in theory reduce global temperatures by reflecting a small percentage of the incoming sunlight away from the Earth. However, the extra particles would also scatter more of the remaining light into the atmosphere. This would reduce by 20 per cent the amount of sunlight that takes a direct route to the ground, and it would increase levels of softer, diffuse scattered light, says Ben Kravitz of the Carnegie Institution for Science in Stanford, California. . . . .
This article in Climatic Change (2006) indicates that this effect can be achieved at a cost of $25 to $50 billion.  
This can be achieved by a continuous deployment of about 1–2 Tg S per year for a total price of US $25–50 billion . . . . 
Compare that to the carbon taxes being proposed for just the United States.  Here is a proposal by Obama that talked about the tax revenue amounting to $80 billion a year.  I have no estimate of the deadweight loss.  From the WSJ:
The cost of energy for consumers would be driven higher in President Barack Obama's proposed budget by a carbon cap-and-trade system that is projected to raise about $80 billion a year starting in 2012. . . .The budget projects raising $645 billion from the auction of emissions credits between 2012, when the system kicks in, and 2019. . . .
The US would probably find it preferable to put the sulphur in the atmosphere all on its own. 


More information is available here.

Remember how Arctic Ice was supposedly disappearing?

For some of the earlier debate, see this post by David Friedman.  I noticed this note at the National Weather service:

THIS HAS BEEN AN EXTREME WINTER FOR SEA ICE IN THE BERING SEA AND NOW
WE HAVE BROKEN THE RECORDS FOR MOST NUMBER OF DAYS WITH ICE AT BOTH
SAINT PAUL ISLAND AND SAINT GEORGE ISLAND.
Th discussion at the DSIDC changes daily so I took this screen shot:



The trend since the late 1970s is available here.  Given that global temperatures have been rising since that point it makes me wonder why they picked that starting date.  But in any case, since 2000, the level of Arctic sea ice has remained at about the same level.

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