Climate change, which has been used interchangeably with global warming, is a highly politicized term, much to climate scientists’ chagrin. It is often discussed in ways intended to confuse or sway public opinion, so let’s stick with the basics: Climate change refers to the change in the usual weather conditions found in a place.
For instance, this winter we are experiencing unusually cold weather for extended periods of time; meanwhile, the Arctic is experiencing unusually warm weather. But when we discuss climate change in a global sense, we are referring to the change in the overall climate of the Earth. This type of climate change is always happening, but on a geologic time scale, over hundreds of millions of years. So how does this relate to the term “global warming”?
Global warming refers to a part of climate change that is happening. This is an important distinction. Global warming was a term coined to summarize the results of human-caused release of heat-trapping gasses (greenhouse gasses) that have been linked to melting glaciers and dying forests. The overall temperature of the planet is warming. When scientists discuss global warming, they are talking about that overall temperature rise. Climate change encompasses that temperature rise, as well as weather extremes, changes in weather patterns and shifting wildlife habitats.
When human activity releases greenhouse gasses like carbon dioxide into the atmosphere, it creates the greenhouse effect. The Earth’s atmosphere traps some solar energy. That energy radiating out into space from the surface of the planet is absorbed in the atmosphere by greenhouse gasses and re-emitted in all directions, instead of into space as it would have otherwise. The energy that radiates back down to the planet heats the lower part of the atmosphere and the surface, thus increasing the overall temperature of the planet.
As I mentioned above, the climate is always changing. The thing that was once debated, and that has been highly politicized, is the rate at which the climate is changing and if human-caused pollution has accelerated it. The consensus among climate scientists is that emissions from human activities has accelerated the rate at which the earth’s climate is changing. Accelerating that rate means that evolution cannot keep up with the changes in weather patterns, which can have devastating impacts to habitats all over the world. Coastal communities like ours are more vulnerable due to rising sea levels, forested areas are more vulnerable to increases in wildfire activity, storms become more intense, we have longer periods of wet weather and of dry weather, causing more floods and droughts.
There are things that we can do to reduce these changes. Carbon dioxide from fossil fuels used to drive cars or run coal-burning power plants is one of the main sources of greenhouse gasses. The second-largest source is deforestation and decay of biomass. Driving less, eating food that is locally sourced and in season, and using less energy and water overall are ways that we can easily contribute to those positive changes. Many of those require changing habits, which can sometimes seem daunting. I suggest starting small. Next time you are about to drive for a short errand, ask yourself if it is necessary. Can you walk or bike there instead, and enjoy the errand that much more? We are fortunate to live in an area that has locally grown produce year-round, taking advantage of that is another way to reduce your personal impact, with the added benefit of the food tasting better because it is in season. Change starts with all of us as individuals.