December 15 , 2017
The Fight against Global Warming
Can humanity really stop the catastrophic global warming from rising emissions of carbon dioxide due to fossil fuel use? The answer is surprisingly, yes. Even with the stupidity of Trump’s sort of withdrawal from the Paris Climate Accords, the actual reality on the ground has become steadily better over the last few years. This optimistic turn of events is not well-recognized, but is probably the most important environmental trend that we are witnessing.
The key change is that the “business as usual” framework we have operated with is much different than it was 10 years ago. Back then, wind and solar were still very expensive, much more than coal, and it was still assumed that industrialization in the developing world would cause them to emit as much carbon as the West had been doing previously. These assumptions went into the “business as usual” (BAU) scenarios that were modeled to predict what would happen to the climate in this century.
Using the assumption of a fossil-fuel (mostly coal) dependent future, BAU meant that we would emit perhaps another 1,500 gigatons of carbon (note, this is the weight of carbon emitted, not carbon dioxide) in this century, leading to massive climate change and up to 5 degrees centigrade of warming by 2100, and 9 degrees by 2300 (obviously predicting climate that far out is sheer guesswork). This is the worst case that the IPCC modeled, known as RCP 8.5. In this version of the future, we never use much solar or wind, and carbon emissions don’t peak but keep rising to triple current levels by the end of the century.
In the last few years, it has become quite clear that that is not the future, even as a BAU scenario. The baseline has dramatically shifted due to a massive plunge in the cost of renewables, and to major policy shifts by China, India, and Europe. Solar and wind are now the cheapest form of electricity, and much cheaper than coal. Coal, which looked like it would be the future of China and India, is on the way out.
The Chinese have canceled 200 coal plants, some of which were already partially built. In the US, existing coal plants have been closing around the country. A little recognized fact is that carbon emissions peaked in the US and Europe ten years ago and are already declining. China expects to peak in the next decade, and India likely will in the 2030s. Combined they hold almost 3 billion people, and if they peak, it likely means the world will have peaked. Some thought we may have already peaked, as carbon emissions were flat in 2015 and 2016 at about 9.5 gigatons of carbon. However, it looks like there was in fact some increase in 2017, but the multi-year trend is clearly decelerating sharply.
Driving the peak of carbon emissions will be the shift to electric vehicles. In the next few years a slew of long range electric cars will be coming on market around the world. India has mandated only electric cars after 2030, as have the French and British. It is likely that we will see the end of gasoline vehicles within the next 25 years. Electrics have gotten much cheaper, and they will be less expensive than gasoline vehicles sometime before 2025. This will be when everyone starts to shift over, with or without government mandates.
In 2016, solar and wind accounted for over half of all new electric capacity around the world. This was accomplished with about 250 billion dollars in investments. Going forward, every year solar and wind get cheaper, while the world gets richer and spends more on green energy. The BAU case now must assume that renewables drop in price by 5% per year (solar dropped 30% in the last two years alone), while the world gets richer by 3% per year. Plug those numbers in and the amount of renewables installed each year doubles in 9 years, and quadruples by 2035. It is obvious that we are going to have a green grid within 20-30 years, even with BAU.
How did we do this? First, there was a vast underestimation of how rapidly solar and wind costs were going to drop, and how quickly we could develop electric cars that were cheap and decent range. Second, Obama’s stimulus program gave a huge boost to renewables. Prior to 2009, the US government had invested less than 10 billion dollars in renewable energy development and research. The stimulus plan poured in 90 billion dollars. One of those programs got Tesla off the ground. Third, the German government made a decision to pursue an “Energiewende” or energy transformation ten years ago. The Germans installed massive amounts of very expensive solar power, which in cloudy, wet, and rather northern Germany, was not exactly the most conducive location to roll out solar. This investment cost German taxpayers dearly, but it provided the needed bridge to help solar prices to plunge to where we are today.
The biggest impediment to renewables is intermittency, meaning where do you get power from when the sun isn’t shining or the wind’s not blowing. There are actually several ways to deal with this. First, wind turbines capture more and more power the bigger they are. The newest turbines are so big that they generate power about 40% of the time which is actually very good. Second, solar is reliable during the day, while wind tends to produce more power at night, allowing the two methods to complement each other. Third, by expanding the grid one can move power around to overcome these problems. A national grid in the US would allow windmills in Iowa to generate power when winds are slow in Texas, and solar in California would still be under daylight when the sun has set on the East Coast. In the future, we could tie solar together across continents even. Solar power plants in Australia could provide North America with power when we are in the dark, and solar in the Sahara can power China and India. Finally, there is the promise of battery storage of power, either in the vehicle fleet itself, or in large utility scale batteries. Battery prices are still too high for massive storage, but batteries are also plunging in price.
In the four IPCC scenarios, carbon emissions rise for the next several years. But then depending on which path is taken, they peak and start to fall, in the best case around 2020, second best about 2040, third best around 2070, and worst case around 2100. It is clear now that we are looking at a peak between 2020 and 2040. Policy action can speed that up or slow it down, but it will be within that range. Which means that our climate change future looks to be between minimally to mildly bad, but not catastrophic anymore. It will mean the difference between holding warming to the 2 degrees above 1,800 level that the IPCC considers to be the goal, and 3 degrees on the worst end.
This is not an argument for complacency, but it is a statement of optimism. Knowing that we are doing well should make us confident that we can achieve the goals we need to reach. I have solar panels on my roof and both of our cars are hybrids. My next vehicle will be electric I’m pretty certain. Ten years ago I would not have predicted any of that. Business as usual has changed tremendously in the last five years.
Ultimately, we will need to remove some carbon from the atmosphere to keep warming to less than 2 degrees. Carbon removal is beyond present-day technology at anything approaching a reasonable price. In the best case IPCC scenario, they assume that we will begin pulling carbon out of the atmosphere around 2075. I’m pretty confident we will be able to do that. The world economy is currently around 100 trillion dollars, but by 2075 it will be somewhere between 500 and 800 trillion dollars. Think about the difference in the global economy between 1950 and now, and it’s not hard to realize the world in 2075 will be unbelievably well-off, and green. That global community will have the wealth and technology to remove carbon from the atmosphere and return us to 300 ppm of CO2 eventually.
