Climate change refers to a range of global changes in weather patterns and temperatures, caused by human activities that alter Earth’s energy balance. These activities include generating power through burning fossil fuels; deforesting land; and altering how and where we grow crops or raise livestock. These changes have a direct impact on local communities and ecosystems.
Scientists have documented a rise in global temperatures since the 19th century, with most of the warming related to human activities. Certain gases in the atmosphere, like carbon dioxide (CO2), block heat from escaping from Earth. This is called the greenhouse effect. When these gases are released into the air through human activity, it warms the atmosphere and makes it harder for plants to absorb the sun’s rays.
When CO2 levels are higher, the warming is more rapid. This is because the warmer air can hold more moisture, which increases storm intensity. The same is true for other greenhouse gases, such as methane and nitrous oxides. The concentration of these gases in the atmosphere has risen rapidly, especially since the industrial revolution.
The concentration of greenhouse gases in the atmosphere is now much higher than it has been for 800,000 years. Based on physics alone, this increase would cause the Earth to warm, but in reality there are feedbacks that amplify or diminish the initial warming.
In response to the growing scientific evidence, thousands of scientists and governments have agreed that we need to limit warming to a safe level to avoid the worst impacts of climate change. This will require a drastic reduction in greenhouse gas emissions. But climate action is just one piece of the solution: We also need to address intersecting crises that compound the causes of climate change, including poverty, racism and inequality.
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