By Dr Anthony Horton
Numerous recent initiatives intend to precipitate action on greenhouse gas (GHG) emissions in the lead up to the Paris Climate Summit, which is now less than 2 months away. In recent weeks, approximately 2000 people and 400 organisations have made commitments to cease investments in fossil fuel producing companies. Countries were asked to nominate actions they would undertake to reduce GHG emissions to the United Nations Framework Convention on Climate Change (UNFCCC) by October 1.
A US Clean Power Plan which was announced in August this year could reduce carbon dioxide emissions from power stations by 870 million tonnes by 2030 (equivalent of taking 166 million cars off the road). China has committed to peak emissions by 2030, and there are indications that emissions may peak before that. Two weeks ago on September 25, China announced that a national carbon emissions trading scheme would commence in 2017. Shortly after that, Brazil announced a 43% cut in greenhouse gas emissions from 2005 levels by 2030.
When the Paris Climate Summit begins, the parties negotiating a deal need to consider the extent to which global warming is already occurring. Global carbon dioxide emissions in 2012 were 58% higher than they were in 1990 and atmospheric carbon dioxide concentrations have increased from approximately 340 parts per million (ppm) in 1980 to nearly 400ppm today. It is a commonly held belief that in order to limit warming to 2°C the total amount of carbon dioxide in the atmosphere must stay below 1 trillion tonnes.
According to the Intergovernmental Panel on Climate Change (IPCC), we were more than half way to 1 trillion tonnes in 2011 with a total amount of 515 billion tonnes in the atmosphere. If global greenhouse gas emissions continue at the rate of 140 billion tonnes each year, temperatures may rise by up to 4.5°C by 2100. Even if each country fully honours its Paris pledge, it is possible that global temperatures may increase by 3.5°C by then.
Global average temperatures are approximately 0.8°C higher than before the Industrial Revolution and a recent study in the journal Science showed that a suspected warming hiatus between 1998 and 2012 didn’t occur-the cooler temperatures arose from measurements from ocean buoys rather than ships. A subsequent study also found flaws in the statistical modelling in the research that pointed to the hiatus.
The world’s oceans are absorbing most of the heat which is being added to the Earth’s climate system. Arctic sea ice coverage in summer has reduced by more than 40% over the past 40 years, and mean sea levels have risen by approximately 20cm since 1880 and could rise by up to 1 metre more by 2100. The Kiribati Government has recently purchased land in Fiji to accommodate residents in the case of flooding.
Given that fresh water is less dense than salt water, melting sheets of ice interrupt oceanic circulation patterns. It is possible that Europe’s climate may cool slightly as a result of the Atlantic meridional driving cold salt water into the deep ocean and warm water northward. The changes in ocean currents may also be shifting jet streams and altering storm patterns.
According to Simon Lewis from University College London, forest fires in Indonesia could release up to 2 billion tonnes of carbon dioxide. Recent US fires have consumed more than 2 million hectares of forest. Alaska fared worst due to soot from the fires darkening the ice and reducing its ability to reflect solar radiation away from the Earth.
The Arctic region is reportedly warming twice as fast as the rest of the Earth, and if the permafrosts (that store 1,700 Gigatonnes or 1,700 billion tonnes of carbon) thaw out, huge amounts of methane will be released. The big problem with that is the global warming potential of methane is 25 times that of carbon dioxide.
In a paper recently published in Nature Climate Change, researchers from Universities of Cambridge and Colorado estimated that the economic impact of both methane and carbon dioxide being released could be as high as 0.7% of global gross domestic product (GDP) by 2200 using environmental models. Their research did however include a high level of uncertainty.
A little more than a week ago Governor of the Bank of England Mark Carney warned that measures necessary to avoid catastrophic climate change in the long term could result in huge losses in the shorter term by rendering oil, coal and gas essentially untouchable.
See more on the 4 degree warming scenario here.
I have to say I admire Christiana Figueres’ persistence in urging immediate action-seemingly on a weekly basis. As overseer of the Paris Climate Summit in December she has an unenviable task in obtaining an unprecedented global agreement. Her task is not made any easier given the justification with which some countries are defending their Paris commitments (despite considerable pressure from others) and their apparent lack of understanding that we are all residents of the one Earth.
Most developed countries understand that the old “business as usual” approach simply won’t cut it anymore and that they have a responsibility to take the needs of people in developing countries into account, especially as the majority of these countries have made little contribution to global greenhouse gas emissions. Announcements are being made virtually every day on social media regarding renewable energy initiatives and/or countries, states or towns that are moving from a reliance on fossil fuels to larger and larger percentages of renewables in their energy mix.
Whether the global average temperature increase by 2100 is predicted to be 2°C or 4°C, it is inevitable that countries need to join together and help each other, including their nearest neighbours. Australia’s recent move to “throw its toys out of the cot” if the UN established an organisation charged with the responsibility of assisting people that are fleeing from the ravages of climate change surely flies in the face of the need to help those around us.
This article was first published on The Climate Change Guy.
