The list of huge impacts of climate change that we are seeing with that one degree rise is pretty much coincident with the list of major physical features that we have on the planet. All of them are, now, in pretty violent flux.

The world’s oceans are about 30% more acidic than they were 40 years ago, that’s a very large change in a very short period of time. Especially on what is after all an ocean planet.

I was in the South Pacific at this point last year working with our crews down there. I happened to be there when this great wave of hot water came across the Indian and Pacific Oceans doing just unbelievable damage to the world’s coral reefs. The Great Barrier Reef got most of the attention because there are reporters and TV stations and stuff in the neighborhood. But pretty much every coral reef across all of the atolls and all the small islands in a matter of weeks, decimated. You talk to coral reef experts who would say I can’t really go down to my plot because I just start crying into my mask and that just doesn’t work.

There was a story last week on the second round of bleaching underway this year at the Great Barrier Reef. One of those scientists said we have given our lives to this project and we have now given up. That is not something that any scientist or anyone says easily ever and it’s obviously hard to read.

I was in the arctic a few weeks ago at the University of the Arctic, well above the Arctic circle. It was the middle of February and it was pouring rain. That day, the temperature at the North Pole was about 50 degrees above average Fahrenheit above average. That’s Sami country up there where people have reindeer herding culture has lasted about ten thousand years but it is in crisis now when it rains like that and then freezes again there is no way for the reindeer to get down to the grass beneath the snow. And if you are a reindeer herder you need to be able to count on the fact that rivers freeze solidly in the winter and when they don’t you fall through them and drown, and people increasingly do.

Maybe the biggest changes so far are to the planet’s hydrological cycle – to the way the planet’s water moves around the earth. The most important fact for the 21st century is probably simply that warm air holds more water vapor than cold. That means that in arid areas we see lots of drought and we see it in horrific form increasingly.

The story on the front page of the Times two weeks ago said that the drought now unfolding across Somalia and environs may be, they have said, the greatest humanitarian crisis since the end of World War II. Millions upon millions of people at the risk of starvation because, as the article also said, more than anything else, the weather patterns, the drought that is there is just unprecedented.

Just like in Syria in the last decade that was clearly now, scientists tell us, one of the key triggers for what turned into to the gruesome civil war there. There were others, our ill advised adventures in Iraq one of them. But the deepest drought in what we call the Fertile Crescent drove a million farmers off of their land into the cities in the course of two years. And it was just more than an already shaky system could even begin to cope with and we now see the result as violence spreads and people fan out across the planet it is unlikely that this is a problem that will be dealt with with tomahawk missiles in any long term way.

There was a picture on the cover of time a year ago – a picture of people dying on the beaches in Greece and Italy and it said, “Are these people climate refugees?” And the answer was in some measure, yes. And obviously they are the harbinger of many, many, millions more as this century goes on.

Its not just drought, once that water is up in the atmosphere, a water molecule stays in the air on average for about seven days and then comes down. And that means that much of the time now more in the flooding crazy rainstorms that are of no use to anybody – that wash away farms instead of nurture them.

In our part of the world we can really feel this. There has been about a 71% increase in that kind of gully-washing storm in the Northeastern United States over the last decades. That is an enormous change. We certainly felt it in the Adirondacks in Vermont when Hurricane Irene came through in 2011 and forever changed the geography of those small steep-sided valleys that simply can’t absorb that kind of water because its the kind of water that they have never had to deal with before.

All of this is with one degree increase Celsius in global temperature. It is entirely clear that we are looking on current trends (even if we implemented all of the things that people promised to implement in Paris) an increase in about three and a half degrees Celsius in global average temperature. About seven, six-seven degrees Fahrenheit. There is no way that we can do that and continue to have civilizations like the ones we are used to.

Already the estimates of how far the sea levels would rise in this century, which a few years ago were on the order of a foot or two, are now on the order of a couple meters and they continue to rise. That puts every coastal city on earth, which is most of the world’s important cities, at deep risk.

This is by far the biggest thing that human beings have ever done. By far. And so far, we are doing very little to try to cope with it.