Posted September 28, 2016
The known unknowns behind climate change forecasting.
Climate scientists are certain that human-caused emissions have increased carbon dioxide in the atmosphere by 44 per cent since the Industrial Revolution. Very few of them dispute that this has already caused average global temperatures to rise roughly 1 degree. Accompanying the warming is disruption to weather patterns, rising sea levels and increased ocean acidity. There is no doubt that further emissions will only make matters worse, possibly much worse. In a nutshell, that is the settled science on human-caused climate change.Continue Reading...
Posted May 18, 2016
Dividing up fair shares of the emissions pie in the wake of Paris
The Paris Agreement on mitigating climate change seeks to limit emissions with the goal of holding the increase in the global average temperature to well below 2 C above preindustrial levels while also pursuing efforts to limit the temperature increase to 1.5 C.
As with any complicated international deal, the devil is in the language. While it acknowledges that developing countries will take longer to peak their greenhouse gas emissions, it agrees that these reductions will be made on the basis of equity.Continue Reading...
Consensus on consensus
Posted April 19, 2016
The scientific consensus on climate change is as strong as ever.
In 1998 and 1999, American scientists Michael Mann, Raymond Bradley and Malcom Hughes published two papers that reconstructed the average temperatures of the northern hemisphere back to the year 1000. The articles showed a temperature profile that gently declined from 1000 to 1850, fluctuating a little along the way, with a sudden increase in the late nineteenth and the twentieth centuries. The graph was nick-named “the Hockey Stick”, with its long relatively straight handle showing the stable pre-industrial climate and the blade representing the sudden uptick in the last 150 years.Continue Reading...
Temperature tantrums on the campaign trail
Posted March 17, 2016
Sorry Ted Cruz. There's no conspiracy among scientists to exaggerate global warming by fudging the numbers.
Last year was the warmest year recorded since the measurement of global surface temperatures began in the nineteenth century. The second-warmest year ever was 2014. Moreover, because of the persisting effects of the equatorial Pacific Ocean phenomenon known as El Niño, many experts are predicting that 2016 could set a new annual record. January and February have already set new monthly records, with February half a degree Celsius warmer than any February in history.
This news is deeply unsettling for those who care about the future of the planet. But it is even more upsetting for people opposed to climate mitigation, since it refutes their favourite talking point – that global warming has stalled in recent years.Continue Reading...
The quest for CCS
Posted January 6, 2016
Carbon capture and storage: solution, stopgap or bust?
Human civilization developed over a period of 10,000 years during which global average surface temperatures remained remarkably stable, hovering within one degree Celsius of where they are today.
If we are to keep future temperatures from getting far outside that range, humanity will be forced to reduce fossil fuel emissions to zero by 2050. Halving our emissions is not good enough: we need to get down to zero to stay under the 2 C target that scientists and policy makers have identified as the limit beyond which global warming becomes dangerous.Continue Reading...