We know it’s getting warmer. Earth’s climate has changed naturally over thousands of years—through cycles of ice ages and warmer periods driven by subtle shifts in the planet’s orbit. But what we’re experiencing today is different. The current warming trend is faster, more intense, and clearly linked to human activity. Since the mid-1800s, the burning of fossil fuels like coal, oil, and gas—along with large-scale deforestation—has caused heat-trapping gases such as carbon dioxide and methane to accumulate rapidly in the atmosphere. These greenhouse gases are blanketing the Earth and intensifying the natural greenhouse effect, locking in more of the Sun’s energy.

As a result, every decade since the 1960s has been hotter than the one before, and the impacts are visible not just in rising temperatures, but across our oceans, ice sheets, and ecosystems. The Intergovernmental Panel on Climate Change (IPCC) confirms that human influence on the climate system has evolved from theory to established fact.

From shrinking glaciers to extreme weather patterns, here are 9 unmistakable signs that prove climate change is real and happening now.