Basically political FUD. I prefer more factual articles such as this:
So What Exactly Is In The Paris Climate Accord?
What is the Paris climate agreement? 9 things you should know
Personally I have looked at climate from a Geological perspective and comparing Earth's temperatures today to the late 19th century is too short sighted. The Little Ice Age ended in the 19th century and global temperatures started rising mid-century. They have been on an upward trajectory since.
Twice in recorded human history temperatures have been warmer than they are now. There was the Roman Warm Period. When Hanibal invaded Italy, he crossed valleys in the Alps that were ice free that have glaciers in them today. Another period was around 1000 AD when temperatures were warm enough for the Vikings to establish a self supporting colony in southern Greenland. Something impossible today. We also know of a very warm period around 6000 BC which was about the time humans started agriculture.
There is also this study that shows the Earth's magnetic field has been growing weaker over the last 150 years and they found a -0.99 correlation between the strength of the Earth's magnetic field. Correlations like that don't prove causality, but it's very rare you have a correlation like that and they aren't linked.
Earth’s Diminishing Magnetic Dipole Moment is Driving Global Carbon Dioxide Levels and Global Warming
All of human history has existed during a brief blip of glacial minimum that happens about every 100,000 years. For the last 2 million years, the Earth has been in these cycles of 90,000 years of glaciation followed by about 10,000 years of ice free, followed by glaciation again. The ice core records from Greenland and Antarctica chronicle the last million years of these cycles, though resolution gets worse as you go back in time. It appears the last glacial minimum was much warmer than this one. A dead coral reef from that time has been found in the middle of the Everglades. That's where reefs could grow during that time.
The ice core records also show that at least some glacial minimums end with a brief (Geologically brief) spike in global temperatures followed by a big crash. The last three spikes haven't triggered a major glaciation period and the inter-glacial periods can be as short as around 8,000 years and as long as around 20,000 years. Depending on where you draw the line of the end of the last glaciation period (it happened in stages), this warm period has last 10,000-15,000 years.
All that said, I still think the US should remain in the Paris agreement and I think focusing on moving away from fossil fuels is a very good idea, whether CO2 is affecting the climate dramatically or not. I think it's possible we may be contributing, but whether we are or not is beside the point.
There are lots of reasons to move away from fossil fuels that have nothing to do with CO2. Fossil fuels contribute to a lot of the world's air pollution and people do literally die because of it. While we're not running out of oil, we have burned up most of the easy stuff to get. The remaining oil to bring online is more expensive to find, more expensive to produce, and adds risks to the environment from the difficulty. The Gulf of Mexico is still heavily polluted from the Deep Water Horizon and it will likely affect the environment for decades.
A lot of the political strife in the world has to do with petroleum politics. If the world didn't need much oil, the Middle East would return to an insignificant backwater and any local wars there would get about as much attention from the rest of the world as wars in Africa do. Not that ignoring wars is a good thing, but it makes a conflict much worse when various players are pouring arms into both sides to try and get a geopolitical advantage.
Russia would also be very different without any demand for oil. Vladamir Putin has become powerful because of Russia's oil and gas exports. With the price of oil down as low as it has been, Russia's economy is struggling. I think several geopolitical players have manipulated the price of oil to keep it low with the aim of starving Putin out of power. It may or may not work, but his economy is in shambles because of it.
Russia is a lot less important to the rest of the world without oil as an economic factor.
The Earth has a very active biosphere that absorbs CO2 very quickly. A way to measure CO2 levels in the atmosphere that is far more accurate than ice cores is to look at the size of the pores in plant leaves over history. It has been found that the pores in many plant species have been getting smaller as CO2 levels have increased. The plant has more than enough, so it reduces the size of the pores to take it in. The correlation between pore size and CO2 levels has been pretty well proven.
Getting historical examples of these plants can be scattershot, but naturalists were collecting a lot of plant samples from around the world in the 18th and 19th centuries and a lot of these samples are still preserved in museums.
Mt Tambora in modern day Indonesia was the largest volcanic eruption ever recorded in 1815. The theory of nuclear winter comes from studying the effects of gases from that eruption on the world climate. Studies of plant samples collected around that time also show world CO2 levels went to almost 400 ppm for a few years, but dropped off over a couple of years as the world's plant life absorbed the extra CO2.
Since then we have denuded way too much vegetation and polluted our oceans, so the ability of the biosphere to absorb CO2 has probably been compromised. We also are putting CO2 into the atmosphere at record levels. The world population is 7 or 8 times what it was in 1815.
Despite all of the above, I still think the US should stay in the Paris agreement and work with other countries. Most activities that would reduce CO2 emissions also move us away from polluting forms of energy into cleaner solutions. With cleaner energy comes a lot of benefits for the environment. It might not directly address things like the damage we have done to plant life on the planet, but it's not going to hurt it and might help a bit.
If you really look at the costs with the climate accord, they are tiny. The coal industry is dying, regardless of what government policy is. This might hasten the demise, but there are already 10X green energy jobs in California alone than in the entire US coal industry. The death of the coal industry is bad news for some big political campaign donors so it's bigger news than it should be. Nobody in politics or the coal company owners give a tinker's damn about coal jobs except as a political talking point.
The climate accord would require the US to chip $3 billion a year into a global fund. That sounds like a lot of money until you realize that's less than $10 a year per American. Most Americans wouldn't even notice.
The green energy industry is already one of the biggest emerging industries. Trying to go back to "drill baby drill" thinking, the US is giving up any advantage it might have in the new economy and it really will be ceding the lead in what will probably replace the global oil business China and any other country that commits whole hog to it.
The FUD critics like to claim that the Paris accords would hurt the US economically, but an actual analysis of the facts of where the world economy is going, emerging industries, and who is on board and who isn't, the opposite is true. Embracing the revolutionary changes coming to the global energy economy guarantees the US will have a place in it. Denying it happens and sticking to old technologies guarantees the US is done as a world power. It will become a technological backwater with antiquated technology and a backwards mindset.
So I think pulling out of the Paris accords was both politically and economically stupid. Maybe for some different reasons than others, but our goals are congruent.
His base is actually shrinking more than polls numbers suggest. Most polls that ask about approval have five answers: strongly approve, moderately approve, neutral/don't know, moderately disapprove, and strongly disapprove. Fivethirtyeight,com did a deep dive into the numbers and found that a lot of people have moved from strongly approve to moderately approve and the number of people who strongly disapprove is at or close to an all time high for presidents.
