Date Posted: October 19, 2011
Print Edition: October 12, 2011
Over the last couple of weeks we have looked at some of the evidence behind the theory of anthropogenic climate change (climate change resulting from human activities). To know why it is happening is one thing, but to realize the implications of rising temperatures and increased CO2 concentrations is entirely different.
There are many arguments that a warmer world would benefit many regions. For example, there have been many discussions in Canadian Parliament, and among other nations bordering the arctic, regarding territorial claims in the arctic. These have been motivated both by the possible natural resources locked away under the ice, and by the observation that the warming climate has begun to unlock the fabled Northwest Passage, a trade route connecting the Pacific and Atlantic that would provide a more direct route than the Panama Canal or the passage around South America. However, melting ice means more water in the ocean; currently, a large mass of ice in Greenland is experiencing notably accelerated melting rates. Greenland contains 10 per cent of the world’s ice mass, and thus has the potential to raise sea levels by up to 20 feet. This could easily flood or completely submerge low-lying areas of the world, such as Manhattan, Venice, or Indonesia. But the melting of sea ice and glaciers has effects reaching far beyond a simple increase in sea level.
Local weather is largely dependent upon differences in temperatures and humidity from region to region. Those dreaming about buying beachside property in Abbotsford and the prospect of our “city in the country” becoming a Canadian California will be disappointed to note that a warmer atmosphere means more water will evaporate into the air, which will lead to an increase in rainfall. In an interview with EarthSky, climate scientist Frank Wentz said that current models predict that areas with already sufficient rainfall will experience increased precipitation, while dry areas of the world will see a decrease in rainfall. This will undoubtedly have a significant effect on fishing and agriculture.
Projected changes in rainfall, as well as shifting local climate patterns, will lead to changes in local agriculture, and not necessarily for the better. While it is true that some colder climates, such as Iceland, have experienced some recent agricultural benefits with the warming, most of the developing world are beginning to see devastating changes in key local crops. Decreased yields in rice, maize, wheat and soybean crops have been tied to current temperature changes; for example, a report published in Proceedings of the National Academy of Sciences of the United States of America in 2004 found that rice yields in Asia have declined by around 10 per cent for each 1°C increase in the growing season minimum temperature. This is simply an additional pressure on the already pressured world food supply. Agriculture isn’t the only resource at risk; changing ocean temperatures are causing fishes to migrate away from their normal ecosystems in search of cooler waters. These changes in ecological systems carry both economic and biological implications.
Increasing temperatures are impacting ecosystems all over the world; the 2007 report by the Intergovermental Panel on Climate Change (IPCC) noted that coral reefs are dying worldwide due to the increase in ocean temperatures. Polar bears rely on sea ice as their habitat, and hunting grounds for marine mammals. With increased temperatures, the seasonal melting of sea ice is happening progressively earlier, and a study done by NASA in conjunction with the Canadian Wildlife Service in 2006 found a decrease of 143 pounds in the average weight of adult females in 2004 when compared to figures from 1980. While more adaptable species of wildlife are likely to remain, the changes in ecosystems due to global warming could very well push many already threatened animal species towards extinction.
There are many other consequences which follow from increased global temperatures that aren’t immediately apparent. Increases in atmospheric and oceanic temperatures are also causing more frequent and more destructive natural disasters, such as hurricanes, tropical storms and droughts. The 2007 report by the IPCC suggested that increased temperatures could cause disease-carrying insects to move northward, further spreading infectious diseases such as malaria. The effects of increasing concentrations of CO2 are far-reaching, and one article does not cover the topic adequately. We must do our part, not only to reduce our carbon footprint, but to raise awareness and work globally, so that catastrophes might be averted. We must remember that our actions have consequences not just to ourselves, but to the entire world.