Climate change cut global wheat and corn output by more than 3% over the past three decades compared to growth projections without a rise in temperatures, a study found on Friday. The impacts translated into up to 20% higher average commodity prices, before accounting for other factors, according to the paper published in the journal Science.
Crop yields rose over the period as a result of improvements in practices and plant breeding, and the isolated, negative impact of climate change was equivalent to about one tenth of those advances.
But that varied widely between countries with Russia, Turkey and Mexico more affected for wheat, for example.
The isolated impact of climate change on wheat and corn was a warning of the future food supply and price impact from an expected acceleration in warming, the paper said.
"Climate changes are already exerting a considerable drag on yield growth," said the study, entitled Climate Trends and Global Crop Production Since 1980.
The authors used crop yield models with and without changes in temperature and rainfall to show global falls in wheat output of 5.5% and 3.8% for corn as a result of climate change from 1980-2008.
That was equivalent to the entire annual corn crop of Mexico, or the wheat crop of France, the European Union's biggest producer, it said.
Nationally, among the worst affected was Russia, with a nearly 15% cull in wheat, while the United States was unaffected.
For soybeans and rice, climate change winners and losers balanced each other out. For example, rice gained in cooler, higher latitude countries.
CO2
The paper, written by scientists from US institutions including Stanford University and Columbia University, noted that adaptation responses, such as advances in crop breeding, could soften the blow of future warming.
"Without successful adaptation, and given the persistent rise in demand for maize and wheat, the sizable yield setback from climate change is likely incurring large economic and health costs," it said.
The study did not account for the impact of higher atmospheric levels of carbon dioxide (CO2), the main manmade greenhouse gas which is also a raw ingredient of, and so spurs, crop growth - called CO2 fertilisation.
Including that effect would likely see a net benefit from climate change on soybeans and rice since 1980, it said.
Conversely, the paper did not account for extreme heatwaves or rainfall, which means the findings could under-estimate the global warming impact.
The output losses since 1980 translated into 18.9% or 6.4% higher average commodity prices, excluding and including the effect of CO2 fertilisation respectively.
The models were based on actual data which showed rising temperatures across nearly all the world's main growing regions with the exception of the United States, which saw a slight cooling over the period. Rainfall trends were more muted.
Concerns have grown in the past few weeks for the impact of droughts on wheat yields in parts of the United States and Europe.
http://www.euractiv.com/en/cap/climate-change-spurred-food-prices-study-news-504655
Climate change has spurred food prices: Study
Industrialised nations fail to deliver on climate funding for developing world
Only two industrialised nations – Russia and Ukraine – have met the 1 May deadline agreed at last year’s Cancun Climate Change Summit to provide details on short-term funding for developing nations tackling climate change.
And according to Reuters, the letters from Russia and Ukraine to the United Nations climate change framework (UNFCC) say only that neither country believes it is ‘required’ to provide a contribution of the $30 billion ‘fast start’ fund for 2010-2012.
A number of developed nations, including the US, Japan and many EU member states agreed to contribute to the fund – and some financing was provided last year.
While the UN is confident that more updates will follow, according to Reuters, the passing of the 1 May deadline will fuel concerns that industrialised nations will fail to honour their commitment to assist developing countries.
The slow progress on raising the initial $30 billion is a setback to the deal, which ultimately promised $100 billion a year by 2020 to developing nations.
Last month the European Commission said the target of $100 billion a year by 2020 was ‘challenging but feasible’ despite the economic downturn across the region, while Commissioner for Climate Action Connie Hedegaard said the EU was “well on tract to deliver its fast start funding”.
But Commissioner for Economic and Monetary Affairs Olli Rehn said that the financial constraints facing many nations rule out public funding and mean that alternative ‘innovative’ funding mechanisms will have to be found.
http://www.energyefficiencynews.com/i/4075/