Good morning, John.  So, the United States is pulling out of the Paris Climate Agreement Treaty Accord Protocol?  I don't, let's be honest, there's a really good chance that you have a strong opinion on the Paris agreement and an even better chance that you don't really know what it is.  There are too many things to know, so, quick timeline.  

350 million years ago, ancient plants covered the Earth, converting the Carbon Dioxide in the air into Oxygen and Carbohydrates.  These plants then die and they create massive mats of organic materials that get buried.  Those organic materials then hang around under the Earth getting heated up and smushed and form energy debts of hydrocarbons, also called fossil fuels.  Notice how Carbohydrate and Hydrocarbon sound similar. 

1882, there was a big gap there.  Thomas Edison builds the first centralized coal-fired power plant.  We'd been using coal for a long time before that of course, but I'm starting here because we have to start somewhere.  For the next 100 years, fossil fuels brought tremendous growth and increases in quality of life, specifically in Europe and America where the vast majority of fossil fuels were burned.

Decades pass.  The benefits of fossil fuels eventually begin to spread and everyone is consuming more and more.  It's great for the most part, except that all that CO2 that was locked up in the fossil fuels for billions of years is now being re-released, and CO2 is really good at letting visible light pass through it, but infrared radiation that gets bounced back up by the Earth does not pass right through it.  It gets trapped.  So the Earth's atmosphere and oceans start having more energy in them, and that starts to change the climate and while fossil fuels give us remarkable abilities to do cool and beautiful things and increase the quality of life here on Earth, we also rely on a stable climate for massive farming operations and coastal infrastructure, by which I mean all the cities that people live in.  

Jumping forward again to 2015.  270 countries get to together in Paris with a goal.  We want to keep the average warming of the Earth below 2 degrees Celsius, because if we don't, it's gonna be really bad for everyone.  But the problem is, no one country can handle this, because even the biggest contributors, the US and China, together make up less than half of the pie.  Everyone needs to agree to make changes or no one benefits.  Worse, the poor countries that have emitted basically zero greenhouse gases are going to be the ones that are most negatively affected by the CO2 that's been released by the wealthy countries because they have more food and water insecurity, less access to good medicine, and less infrastructure.  It's very difficult to say to them, no, don't grow your economy using the same dirty fuels and techniques that we used to grow our economies.  Instead, buy these solar panels from us with the money you don't have.  Also, like, since any country that keeps burning its usual will have a competitive advantage in industry.  Everyone agrees that everyone needs to agree or this agreement is useless.  

With advice from scientists, the countries all together determined how quickly the Earth needs to stop emitting greenhouse gases to meet the 2 degree goal and then based on how developed each country is, how many people they have, and how much they're currently emitting, they divvied up that responsibility.  At the end, every country had a goal.  There was no enforcement for meeting that goal, but there was a goal, and some countries that had already benefited a lot from the last 100 years of releasing carbon dioxide even threw in some money, billions of dollars to eight countries that hadn't benefited from that to help them grow with less reliance on fossil fuels.  Every country agreed to their own path forward, and every country was responsible for figuring out how to meet their goals, whether it's through energy efficiency, subsidizing renewables, regulating businesses, changing peoples' behavior through indication, or ending fossil fuel subsidies, and if countries don't meet their targets again, nothing happens, there are no penalties.  This is an agreement between nations that there's a problem and we must lead together or face the price and remarkably, a treaty that only encourages countries to increase emissions with unenforceable promises is a gigantic step and one that has already seen significant success.  But this is an investment and it does have costs.  

Do we know exactly what that price will be?  No.  We don't know precisely how much better off we'll be if we keep temperatures from rising more than two degrees Celsius and we don't know precisely how much we need to reduce greenhouse gas emissions to hit that target, but we do know that we are better off incentivizing these changes now globally, because more than 600,000,000 people live in areas threatened by sea level rise.  Every person on Earth has to eat every single day, and climate refugees, lost crops, and lost infrastructure could destabilize the entire world economy and result in a very era of human history, a sentiment to which the US Department of Defense, by the way, agrees.  

Remarkably, thanks to a combination of energy efficiency, changing habits, and a shift from coal to natural gas and renewables, the United States was, until recently, on target to meet its Paris goals for decreasing emissions 26% from 2005 levels by 2025.  We've already decreased emissions by around 14%, even as the economy has grown, but if there is no political will to continue this, if the majority party in both houses of congress and the president do not agree that humans are causing climate change and what to continue investing in the same energy systems Thomas Edison pioneered in the 1800s, we will stall.  

Other countries, at the moment, are pledging to move forward, leading in the absence  of the United States, and several states in the US, the ones with the largest economies, also have plans to abide by the agreement.  But without the US, a country that emits 18% of the world's greenhouse gases with just 4% of the population, this pioneering agreement is considerably weakened.  After all, why would other countries hold up their side of the bargain if the country that benefited the most from the carbon dioxide currently in the atmosphere shirks their responsibility?  

I, for one, am tired of politicians pretending that we don't all share this big, beautiful, but also quite small planet.  I was proud that my country was a leader in establishing the Paris agreement, and I am ashamed at the step backward we have taken away from uniting humanity to take on this great global challenge.  John, I'll see you on Tuesday.