Читать книгу Climate Change For Dummies - Elizabeth May - Страница 49

Since the Industrial Revolution went into full swing around 1850, the amount of GHGs in the atmosphere has risen drastically. Due to burning fossil fuels, as well as clearing forests, people have almost doubled the carbon dioxide emissions in just over a century, and today, carbon dioxide levels are higher than they have ever been in recorded history (see Chapter 4 for more about fossil fuels). In fact, atmospheric carbon dioxide levels are higher today — a 45 percent increase — than at any time in the past 800,000 years. (Carbon dioxide levels were much higher millions of years ago, however. We talk about the history of carbon dioxide levels in greater detail in Chapter 3.)

Carbon dioxide concentration levels are currently at about 412 ppm, and they rose at an average of 2 ppm per year between 2000 and 2021 because of increasing emissions due to human actions. On average, in the 1980s, globally, people put 7.2 billion metric tons of carbon dioxide emissions into the air every year — and those emissions have been increasing every year — now at 43 billion, per the Center for Climate and Energy Solutions. So many people are using so much energy, mostly in industrialized countries, that the amount of carbon that is being put into the air is knocking the carbon cycle off balance.