Global Warming

Climate change is already affecting global food production - unequally

The world's top 10 crops -- barley, cassava, maize, oil palm, rapeseed, rice, sorghum, soybean, sugarcane and wheat -- supply a combined 83 percent of all calories produced on cropland. Yields have long been projected to decrease in future climate conditions. Now, new research shows climate change has already affected production of these key energy sources -- and some regions and countries are faring far worse than others.

Published in PLOS ONE, the University of Minnesota-led study, conducted with researchers from the University of Oxford and the University of Copenhagen, used weather and reported crop data to evaluate the potential impact of observed climate change. The researchers found that:

- observed climate change causes a significant yield variation in the world's top 10 crops, ranging from a decrease of 13.4 percent for oil palm to an increase of 3.5 percent for soybean, and resulting in an average reduction of approximately one percent (-3.5 X 10e13 kcal/year) of consumable food calories from these top 10 crops;

- impacts of climate change on global food production are mostly negative in Europe, Southern Africa, and Australia, generally positive in Latin America, and mixed in Asia and Northern and Central America;

- half of all food-insecure countries are experiencing decreases in crop production -- and so are some affluent industrialized countries in Western Europe;

- contrastingly, recent climate change has increased the yields of certain crops in some areas of the upper Midwest United States.

Marine Species More Vulnerable to Global Warming Than Terrestrial Species

A new study published in the journal Nature reveals that marine species may be more susceptible to global warming effects — specifically increases in temperatures — than land creatures.

All organisms, whether you’re warm-blooded or cold-blooded, have this range of temperatures that you can tolerate before your body starts to shut down and experience serious physiological stress — a lower bound and an upper bound. And so with warming, we’re mostly concerned about the upper bound because these temperatures are getting hotter and hotter.

The scientists compiled the upper thermal limits for 406 total ectothermic species — 88 marine and 318 terrestrial — and assessed their position relative to the temperature threshold before they would begin to experience heat shock or heat stroke.

It turned out that in the ocean, marine animals were sitting much closer to that maximum, much closer to this ceiling where they would overheat and get into a real physiological stressful situation than terrestrial animals were, on average — which means that there is then less buffering for them to get to these overheating points in the ocean.

In addition, the scientists found that local species extinctions in the ocean occurred at twice the rate than those on land. Marine organisms may also have heightened vulnerability and sensitivity to thermal stress because they experience less thermal variability on average than do land creatures. During the transition from winter to summer or even across the duration of a day, a temperature logger tracks noticeably greater changes on land than in water.

Marine species haven’t needed to worry about temperature fluctuations as much, leaving them more disadvantaged to deal with the rapidly rising ocean temperatures.