More info from The Climate Reality Project

Since 1880, the world has warmed about 0.8 degrees Celsius, or about 1.5 degrees Fahrenheit.

Doesn’t sound like much, does it?

Of course, that’s the average temperature increase for the entire planet. Averages tend to hide important detail. For instance, the murder rate in the American West declined 0.1% between 2010 and 2011. But that’s probably not too comforting to the residents of San Jose, California, where the murder rate nearly doubled over the same period. Similarly, some parts of the world are warming much faster than the global average — including Arizona, which since 1970 has been warming more than 0.6 degrees Celsius per decade!

Even 0.8 degrees has been no picnic. For instance:

Extreme weather is getting worse.

Around the world, the hottest days are getting hotter and rainstorms and droughts are getting more intense. These extreme weather events are a threat to our health, our ability to move from place to place, and our overall economy.

Sea levels are rising.

Coastal areas around the world are already grappling with the effects of rising seas. Take Bangladesh, for example, where salt is creeping into drinking water. In Norfolk, Virginia, officials and homeowners are dealing with increasingly frequent coastal floods. And the shores of low-lying nations like Tonga are being eaten away by rising waters.

Plant and animal species are declining.

Ice-dependent species like polar bears are faring the worst so far, but scientists are seeing trouble in everything from blackbirds in Canada, to butterflies in the U.K., to fish in Zimbabwe.

All that with just a 0.8-degree increase! Now consider that we are on track for another 6 degrees Celsius (11 degrees Fahrenheit) of warming by early in the next century — unless we drastically limit carbon pollution from fossil fuels, that is. What would 6 degrees mean for people around the world?

One thing’s for sure: Things aren’t going to get any easier. In fact, a report (PDF) from the National Research Council suggests that for every degree of global warming, the world could see a 3-10% increase in the amount of rain falling in extreme storms, a 5-15% reduction in crop yields, and a 200-400% increase in the area burned by wildfire in the American West.