Climate science – Page 72

Climate Change and Global Energy Security

Academics Marilyn Brown and Benjamin Sovacool, who have impressive credentials in the field of energy policy, are co-authors of the recently published Climate Change and Global Energy Security: Technology and Policy Options, a substantial and detailed study of a very wide range of technologies covering both the promise of those options and the obstacles to their effective employment.

I was deeply depressed by the time I got to page 64 of the book. That was where the tale of five challenges ended. The authors had enlarged the energy and climate change scope of the book somewhat to identify five challenges threatening the prosperity of future generations: electricity, transportation, forestry and agriculture, waste and water, climate change. They do it thoroughly, and it seemed well-nigh impossible that the growing population of the world could possibly cope with these problem areas. But the reader is counselled in the final paragraph of the chapter not to give up in despair, as the issues can be broken down into more manageable challenges to which technology and policy solutions are readily available. Continue reading “Climate Change and Global Energy Security”

A lecture not to miss

Tim Naish’s lecture, of which we gave notice recently, is now recorded on the Climate Change Research Institute’s website. I warmly recommend it for viewing. Naish is one of the lead authors for the paleoclimate chapter for working group 1 of the IPCC Fifth Assessment Report due in 2013. In this lecture he uses paleoclimate material to provide perspective for the projections of rising global temperature and climate change. We are headed for climates and temperatures that haven’t been seen on the planet for more than a million years and the paleoclimate record helps us to understand what we might expect in terms of polar ice behaviour and sea level rise.

In fact we have to go back 3 million years – to the mid-Pliocene – before we see temperatures like those the models are projecting, 2 to 3 degrees warmer by 2100. The atmospheric CO₂ level then was about 400 parts per million. This Pliocene warm period is becoming an important window into what we might expect incoming decades. Continue reading “A lecture not to miss”

Natural Gas is Not a Green Fuel

My heart sinks when I read enthusiastic acclamations of natural gas as a substitute for coal. It releases less CO₂ on combustion, we’re told. It is a good bridge to the time when renewable energy is sufficiently developed to take over. And latterly, with the development of fracking, that’s going to be a very long bridge. There are claims that if we can extract all the shale natural gas there’s enough to keep us supplied for 200 years. And in addition there’s the wonderful supply awaiting extraction from methane hydrates in the ocean once we find out how to do it.

The oil and gas companies even hail it as a green fuel. It’s no such thing. Natural gas is a fossil fuel. It releases CO₂ when it is burned. It may be preferable to coal, but it is no solution to the crisis we are confronted with. And there is in any case doubt being cast on its superiority to coal, especially when it is obtained by unconventional means. In a paper published in Climatic Change Letters earlier this year Howarth et al evaluate the greenhouse gas footprint of natural gas obtained by high volume hydraulic fracturing from shale formations, focusing on methane emissions. Continue reading “Natural Gas is Not a Green Fuel”

Climate Change: The Long View

Professor Tim Naish, Director of the Antarctic Research Centre, Victoria University of Wellington, and Principal Scientist, GNS Science, is giving a lecture tomorrow, Thursday 15 September, from 12.30-1.30 at VUW’s Pipitea Campus, Railway West Wing 501. It’s part of the NZ Climate Change Research Institute’s Seminar Series. Recommended to Wellingtonians, and worth attention from the rest of us for its sobering content indicated below.

Climate Change: The Long View

Computer models can now reliably reconstruct Earth’s climate over the last 150 years, including the rise in average global temperature of 0.7º C in the last century. When they are used to project Earth’s climate to 2100 under a range of greenhouse gas emissions scenarios they indicate average global temperature increase will likely be between 2 and 5ºC. Even at the low end, which requires an aggressive reduction in emissions, this is higher than at any time in the last million years, based on well established paleo-temperature records.

The last time Earth experienced such a climate was 3-5 million years ago. During this period known as the warm Pliocene Epoch, atmospheric carbon dioxide was near present day levels and average surface temperature was ~3°C warmer, but sea-level was up to ~20m higher, largely from ice sheet melt. In the last 50 years the polar regions have warmed at almost twice the global average, and the last decade the ice sheets have begun to melt. One of the key questions being addressed by the scientific community for the IPCC 5th Assessment Report is improving estimates of future sea level. This talk will outline progress in the use of past temperature, ice sheet reconstructions and sea level records in addressing this issue.

It isn’t the sun

The recent CERN paper in Nature on cosmic rays and cloud formation has caused considerable excitement in the denialist world. Canadian columnist Lawrence Solomon in the Financial Post declared “The new findings point to cosmic rays and the sun – not human activities – as the controller of climate on Earth”. For what the paper really said readers can turn to the welcome and discussion it received on RealClimate. There’s also a useful response to Solomon’s claim on SkepticalScience.

It’s a complex picture, but today I came across this short video which sets it out straightforwardly and with a light touch. (Thanks to The Carbon Brief website.) Put together by Australian science journalist Potholer, it is both an explanation of the science and a picture of how misinterpretations travel in the denialist community.

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