What is Climate Change?

Preventing Climate Change is often quoted as a main reason to increase the use of renewable energy sources including solar energy. But what is climate change? And do we really have to care about it?

What Is Climate Change?

Climate change is something that has been going on as long at the Earth has existed. The term refers to distinct changes in average temperatures measured over a long period of time. One of the most dramatic climate changes we know is what probably happened when the dinosaurs became extinct. Presumably a large meteor hit the Earth and resulted in enough dust to reduce average temperatures significantly about 65 million years ago.

When we speak about climate change today, it is most often in connection to the risk of human-induced climate warming, i.e. global warming.

Why Is It Happening?
Climate change can and will always have natural causes, such as changes in the sun's energy levels or the Earth's orbit around the sun. Also completely natural processes, unaffected by human activity, such as changes in ocean circulation, will cause slow climate changes.

The problem is, however, that in addition to these natural processes, the exponential increase in fossil fuels during the past two hundred years seems to causing climate change as well. With the start of the Industrial revolution, we are burning fossil fuels and changing the land surface (e.g., cutting down forests, planting trees, building developments in cities and suburbs, etc.), in ways that severely increases the amount of so called greenhouse gases gathering the atmosphere.

The burning of fossil fuels and other human activities are adding large amounts of carbon dioxide and other greenhouse gases to the natural mix at a faster rate than at any other time on record. Other important greenhouse gases produced by human activity include methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulfur hexafluoride(SF). Atmospheric concentrations of CO2, CH4 and N2O have increased by over 36 percent, 148 percent and 18 percent, respectively since 1750. Is that enough to actually affect the Earth's climate?

Well, the Intergovernmental Panel for Climate Change (IPCC) scientists believe that there is a greater than 90 percent chance that most of the warming we have experienced since the 1950s is due to the increase in greenhouse gas emissions from human activities.

And What Are The Effects For Me?

Then how serious is this?

Pretty serious, actually. Even if some lobbying organizations (especially those liaised with the oil industry) have been playing down the risks and consequences for a long time, the vast majority of recent research points in the same direction - depending on how we quickly we act to reduce the emissions of greenhouse gases, the Earth average temperature will change more or less drastically over the next hundred years. IPCC works continuously with several different scenarios regarding the world's economic, environmental and population development, to model potential effects on our climate. Depending on what scenario you believe in, the world's average temperature will have increased by between 1 and over 6 C degrees. This in turn is projected to lead to sea level rise of up to 0.6 meters. (Or more, if the ice melts faster.)

But isn't it nice to have warmer weather?

Well, sure, in some places it might actually be nicer weather. But that doesn't mean that it is necessarily better. We are talking about a very rapid change (from a climate evolution perspective), and there is a high risk that for example crops will not adapt, even in parts of the world where an average temperature sounds quite nice. In addition, 20 to 30% of species assessed so far are likely to be at increased risk of extinction if increases in global average warming exceed 1.5 to 2.5C.

Video Explanation

Want a visual explanation of what climate change is? Then take two minutes to watch this video.