The USDA published a new Plant Hardiness Zone Map based on the average annual minimum winter temperatures. Growers and gardeners use the map as a guide to determine which plants are most likely to thrive at a location. When the new guide came out, it was evident that the hardiness zones had shifted further to the north. This is a clear indication that the plants feel that the weather is warmer. Some lettuce plants that sprouted in the fall in Washington, DC survived the winter without freezing. Washington’s famous cherry trees reached peak bloom two weeks earlier than usual, and the Cherry Blossom Festival had to be held earlier. By the end of March, which is the usual time of the festival, the flowers were gone and the ground and the cars were covered with cherry blossom petals.
The release of the new hardiness map did not mention global warming because this is a political hot topic in the United States. If global warming is accepted as a fact, there are economic implications. For example, carbon dioxide and other greenhouse gases will have to be controlled by reducing the combustion of fossil fuels. This would reduce the profits for energy producers, car manufacturers, and many other industries. To maintain the current business models, it is better to deny global warming and continue burning fossil fuels. There is another reason why manufacturers would like to keep the status quo. If the cost of fossil fuels is raised to try to reduce their use, new alternative fuel technologies and green power sources will be developed to compete with existing industries. This is bad for the businesses that profit from the consumption of fossil fuels. They will be like the buggy whip manufacturers that eventually went out of business when internal combustion vehicles replaced horse-drawn carriages and became the main mode of personal transportation at the beginning of the twentieth century.
Global warming poses a real threat to our ecosystems, including the risk of mass extinctions. The winters with little snow, tornadoes before springtime, rising sea levels, and early blooming of trees are all signs of warmer weather. The rise in temperatures is correlated with the increase of atmospheric carbon dioxide which started with the industrial revolution. It is getting harder and harder to deny the impact that our industrialization is having on our planet.