The last four years were the four warmest years on record (in the order 2016,2017,2015 and 2018). Since 1880 the average surface temperature on Earth has risen by about 1 degree C, 0.79 degrees above the 20th century average. At the same time global ice is decreasing, especially in the arctic which is losing 12.8% per decade. Sea level is also rising – in 2014 the average sea level was 2.6 inches above the 1993 average.

These numbers are all clear, but are abstract for most people. If scientists didn’t tell us the planet was warming on average, we wouldn’t see it in our daily lives. This made it easier to engage in politically motivated denial. The science is also complex, which leaves a lot of room for rationalization. You can focus on different types of measurement (surface temperatures vs atmospheric, for example) or on the need to adjust the raw data to account for historical changes in measurements. You could play games with the statistics to manufacture an illusory “pause” or focus on the uncertainty.

To be clear, carefully examining the details is critically important. The problem is when you do so with an agenda other than objectively describing reality. There is enough wiggle room to convince yourself of whatever it is you want to believe.

The needle appears to be moving, however, not because the science has become more solid, but because the effects have become more obvious. Extreme weather events are also significantly increasing, by about 40% since 1950. Just in the past year we had record breaking fires on the West coast, record breaking tornadoes in my home state of CT, and now record breaking polar vortex driven cold in the midwest. We are seeing more powerful hurricanes, like Hurricanes Florence and Michael.  There are record breaking heat waves around the world, with Death Valley having the warmest month ever recorded on Earth last July.

These extreme weather events are apparently having an effect. A recent Yale survey found that 51% of Americans are either extremely or very sure that global warming is happening. This is up from 37% in 2015. That’s still low, but at least it’s a majority. The numbers are even higher on other surveys. If simply asked if you agree with the statement, “Climate change is happening,” 75% in rural areas agree, 79% suburban, and 84% urban. So generally a majority of people agree that global warming is happening, and they also agree that we should do something about it, including reducing CO2 production.

You would think this is enough to have a strong political consensus to take action, but apparently it isn’t. The Republican party still is ideologically in a state of global warming denial, even as there is a small minority seeking solutions, and even as Republican citizens are coming around to accept this reality.

What previous research has shown is that much of this denial is really “solution aversion” – it derives from opposition to some of the proposed solutions, like a carbon tax. The “solution aversion” has taken on a life of its own, and evolved into full-blown conspiracy theories about climate change being a hoax the purpose of which is for liberal governments to seize control of the energy sector (and also to line the pockets of those greedy scientists).

The point of global warming denialism is to do nothing. That is the goal, and deniers don’t seem to care how they get there. They reverse engineer justifications for that conclusion ad hoc and opportunistically. So – the default position is to deny that global warming is happening. When the data become too clear to deny, they retreat to a position of, “The globe may be warming, but it is a natural cycle, not man-made.” When the data skewer that position, the retreat further to the position that warming may be happening and may be man-made, but it’s not a problem. It may even be a good thing. Scientists are pretty clear that the potential effects are dire, and economists are now chiming in calculating the billions of dollars global warming will cost. So they retreat even further, to the position that there is nothing we can do about it, it’s already too late, so we might as well adapt.

This strategy is sometimes called the “Motte and Bailey” gambit, after a fort design. As your defenses crumble you retreat to more defensible positions, but then venture back out when able. Deniers will reluctantly acknowledge that global warming is happening when they must, and retreat to another justification for doing nothing, but then seize upon any bit of data or analysis they can use to argue that global warming is not happening after all. They never fully abandon their more audacious positions. Again – the point is to conclude that we should do nothing, and the various positions are all just a means to that end.

It’s all extremely irrational, but consistent with human psychology. It’s also frustrating, because the science is solid and the consensus is strong. Of course, they attack the consensus also, with more misdirection. In fact there are multiple studies calculating the percentage of working climate scientists who agree in anthropogenic global warming, and the numbers cluster around 97%. There is a consensus about the consensus.

The political conversation we should be having right now is about creative solutions. Any money we spend now to mitigate global warming is likely to prevent many times that expense dealing with the effects later on. Reducing pollution will also save lives and reduce damage from extreme weather events. Dealing with global warming is cost effective and will have a huge impact on quality of life. There are also many free market approaches that don’t trigger the globalist Marxist nightmares of conservatives.

It’s unfortunate that, generally speaking, bad things have to happen before people take notice and do something. Diseases had to come roaring back before the threat of the anti-vaccine movement was generally realized, for example. The same is true of climate change – people need to see the extreme weather events and suffer the effects before getting serious (and even then).

The real question is – how bad will it have to get to create sufficient political will to take effective action, and will it already be too late?