The earth’s climate has changed a lot over 4.5 billion years. Before human beings even existed, the earth experienced at least five Ice Ages and warmings due to small changes in its orbit. Since the last Ice Age, Earth has had a climate ideal for supporting human life. But now, a new type of climate change threatens our existence, and it’s not due to the shifting of Earth’s position in relation to the sun — it is because of humanity’s own actions. The excessive burning of fossil fuels is causing the climate to warm, and the effects will devastate the planet we call home.
Since the Industrial Revolution, humans have made wonderful advances in technology, but we have also increased our use of energy. Right now, humanity’s main sources of fuel are coal, gas and other fossil fuels that are burned to release energy. When they are burned, they rapidly release carbon dioxide and other greenhouse gases that pollute the atmosphere. The cycling of carbon is a natural process in our ecosystems, and carbon has many natural reservoirs, like forests and underground rocks. But we are releasing too much carbon at a faster rate than our carbon reservoirs can absorb. That means that these greenhouse gases linger and build up in our atmosphere and oceans. These greenhouse gases over-insulate our planet, trapping the sun’s heat much longer than is normal before it escapes back into space. This trapped heat raises global temperatures.
Scientists measure global climate of the past by looking at ice cores, fossils, sedimentary rocks, and tree core samples. Satellites orbiting the planet and a network of sophisticated scientific instruments on earth are used to measure recent climate change. Our planet’s temperature has raised approximately two degrees Fahrenheit over the past 100 years, and most of that change has happened in the past few decades. Two degrees may seem small, but measuring climate over a long period of time is different than measuring the daily temperature. The difference between the climate of the last Ice Age — when the United States was covered in 3,000 feet of ice — and today is less than nine degrees Fahrenheit in total. By measuring the climate in recent years, scientists have seen a pattern of longer and hotter summers. Extremely cold winter days are less frequent and the number of extremely hot days per year is increasing. For the past decade, we have had some of the hottest years for the global temperature in human history.
The overwhelming majority of scientists agree that global warming is caused by human activity and the burning of fossil fuels. As the global climate continues to rise at this rapid rate, scientists predict that in the next century there will be more frequent natural disasters and many inhabited parts of the earth may become too extreme for human life. But there is hope! If humanity works together to reduce the amount of greenhouse gases in the atmosphere, we can slow down and maybe even stop the negative effects of global warming. By changing how we use our resources, we can give people and the planet more time to adapt to our changing climate.