Since about 1975, earth has been heating up at a rate of about 0.018oC/year. Frankly, that’s not much in a single year. In fact we can’t really measure the global average temperature that accurately.
But over many years, the heating adds up. In a decade, it’s about 0.18oC, and we can measure that. Still, it doesn’t seem like much — slightly less than half a degree Fahrenheit. But in ecological terms it can have important consequences. Snow melts earlier, altering the water cycle; fewer insect pests die out due to winter freezing; glaciers begin to melt worldwide; plant and animal species slowly migrate poleward.
