Can We Stop Global Warming?

There are a massive number of articles out there about global warming and the Paris agreement. The goal was to stay under 1.5 degrees of warming and our absolute limit was 2.0 degrees of warming. I rarely, if ever, see articles that talk about the feasibility of any of this though, and I figured I'd write my blunt assessment.

Scale of the problem

What level of emissions cuts are we talking about here? I put up a tool recently that lets you see emissions projections and requirements, and here is a screenshot showing a best case scenario if we wait a decade to start dramatically lowering our emissions:

That looks insane. We'd have ~15 years to completely stop all emissions if we want to meet the bare minimum Paris goals. That's not 'halve emissions from electricity production'. That's not 'switch to electric cars'. That's stop all emissions. That's to have any hope of preventing catastrophic global warming. That won't even guarantee we make it...that just gives us a better than 50/50 shot. Feel free to play with that tool to get an idea of what we're dealing with.

The y-axis there is global CO2 emissions. You can see that they're around 40 gigatons per year. What does that really mean? To give a sense of scale, here is a list of some actions that would cut ~10% of that (3.6 gigatons per year) (most taken from here):

1. Double the fuel economy of all cars
2. Cut our total driving in half
3. Quadruple our wind power production and shut down a corresponding amount of coal production (this is a new wind farm the size of Arizona)
4. Cover an un-forested area the size of India with forests
5. Convert 15% of the world's cropland into biofuel production
6. Triple our number of nuclear power plants and shut down a corresponding amount of coal production

Any one of those would be extremely impressive in a developed nation and absolutely incredible in a developing nation. If we did all six of them globally, it would still not be enough. We have to stop increasing emissions and do more than that list. We're actually going in the wrong direction in that we're increasing emissions every year. The longer we wait, the more drastic the required cuts.

It gets worse...

Mitigating the effects of climate change will lead to more emissions. Many areas will experience greater droughts. One mitigation is desalination. Desalination uses a non-trivial amount of energy. Another mitigation is to increase crop watering. That also uses energy. Many areas will have extreme heat waves. Heat waves lead to air conditioning usage which leads to surges in power demand which leads to increased usage of backup systems which are fossil-fuel based. Rebuilding and migrating due to flooding will lead to emissions increases. Hell...even producing solar panels and wind turbines emits greenhouse gases.

It gets worse...

The population is increasing. More humans generally means more emissions. More humans generally means more cropland is required which means less land for carbon-capture and more emissions through deforestation and poor soil management.

It gets worse...

Some positive feedbacks have already kicked in. The world's forests are starting to emit carbon. The permafrost is melting and releasing greenhouse gases. Arctic sea ice is melting and lowering our net albedo (this is particularly devastating for the northern hemisphere). I noted that what I included above is a best case, and it is because it doesn't factor in these or the next one...

It gets worse...

Parts of the world are switching to natural gas instead of coal. This is releasing much more methane than originally thought. Methane is an extremely potent greenhouse gas. Our switch to natural gas didn't mitigate global warming in the ways we thought which makes our targets much more difficult.

It gets worse...

We effectively eat fossil fuels. They are used as a productivity multiplier for almost everything our economy is based on. Suddenly dropping them would lead to catastrophic drops in global productivity. For reference, the great recession that devastated much of the world late last decade was a ~3% decline in GDP for a single year in the US. Can we really expect the world to voluntarily enter a probably larger and longer decline to prevent this?

It gets worse...

Energy companies and governments have known, claimed reserves. The value of these reserves is factored into our economy. If we burned all of these reserves, it would blow way past our carbon budget and push us into extreme global warming (see worst case impacts below). Can we really just leave all of that fuel in the ground and suffer the economic fallout associated with that?

Maybe we can just miss our targets?

Impacts of global warming

On the left sidebar on desktop, you'll see some of the impacts of global warming. You can get it through this link on mobile. They are varied and extremely unsettling. It's impossible to accurately summarize them, but I'll give it a shot.  Aggregated from a large number of sources (I'll list a sample) and stated assuming little real mitigation:

• people will die in massive numbers (dara, WHO, various)

• we will experience permanent/perpetual economic setbacks of at least several % GDP per year (summary with sources)

• food productivity will suffer (various, NRC, Stanford)

• we will experience loss of habitable land and mass migrations due to sea level rise (Bangladesh, everywhere, Maldives) and temperature increases (obvious, Middle East)

• we will experience unbelievably brutal droughts and lack of water (US west/southwest, global, southern Europe, Peru)

• we will experience brutal heat waves (obvious)

All of these are obvious and you can find a massive list of sources...I just included the ones that I had handy because I hate it when articles don't provide easy access to sources. The scope is much greater than what I cover there. You can also nit-pick individual sources there...it changes nothing...a wide variety of sources covering a huge number of effects representing scientists all over the world come to the same basic conclusions. They still don't quite convey the scale of the issue though as they're generally targeted so you might miss the big picture. I'll just brain dump a more casual list here to give an idea:

• how many major airport runways are <6 feet above sea level? what about major highways?

• what happens to naval yards and sea ports when sea level rises dramatically?

• what happens to shipping and international trade given the first two bullets?

• what happens to distribution of things like vaccines and drugs given the previous bullet?

• how many aquifers are at risk of salt water coming in as sea levels rise?

• can we still be productive when it becomes too hot to work outdoors during the day for months at a time?

• if the world was devastated by a one year <3% drop in GDP, how will we respond to a permanent, >3% drop in GDP?

• how do you buy food and energy when they become more expensive while we're already suffering from the drop in GDP?

• how much more will the economy suffer when people start leaving Texas, Arizona, etc. and real estate for entire regions loses value?

• what happens when the great plains and southern Europe become arid? the last dust bowl was short and isolated and still led to mass migration...

• do hydroelectric dams still work once long-term/permanent droughts set in?

• what impacts will a long-term refugee crisis an order of magnitude larger than Syria's have on global relations?

• what will nuclear powers like Pakistan do when they start running out of water?

• how much will the inevitable wars from all of this affect the economy?

• did planning for nuclear plants built on coastlines factor in sea level rise?

Now for some stretch ones that are poorly understood currently (note that means we could be overestimating them but also that we could be underestimating them):

• will permafrost melt release so many greenhouse gases that it stops mattering if we reduce emissions?

• will ocean acidification really devastate sea life?

• what happens if hurricanes do get significantly worse?

• can we contain wildfires that increase in range, frequency, and intensity while all of the other stuff is going on?

• what happens if we are wrong on climate sensitivity and we're really heading for a >5 degree temperature rise in our lifetimes due to increasing feedbacks?

Most of these increase in scale as temperatures rise. For example, GDP losses are likely in the 1-2% range with heavy mitigation and the 5-10% range without it. Crop production likely drops by 5-10% per degree of temperature increase, especially above 2 degrees. Sea level rise probably doubles with high emissions vs low emissions.

It is very important to understand that this isn't a distant future problem. This is already happening. This is already killing people, exacerbating droughts, etc. It will continue to get worse. 2030 will be worse than now. 2050 will be worse than 2030. This directly hurts your children. Quoting Joseph Romm..."Climate change will have a bigger impact on humanity than the internet has had."

Maybe we shouldn't miss our targets by too much then?

*Additional major sources for much of the above are the IPCC reports, book 1, book 2, Royal Society update, and the US Climate Assessment. Some of this is also just common sense...as sea levels rise, things like runways that will now be below sea level become an issue, and many major airports were built on coastlines.

How do we stop global warming?

To be blunt...I don't think we can. Given what it would take from the first section of this post and the fact that people have known about this for many years and only made the problem worse, I don't think we'll actually come close to stopping it. I'm hoping we'll at least make it not as bad as it can be, but we actually seem to be getting worse. In the US at least, the GOP over the last decade has switched to open science denial. Voters rewarded them by electing Trump and giving the GOP control of all branches of government. When faced with a comparatively small refugee crisis, the world failed to band together and deal with it.

Also, much of the above is locked in. Even if we cut all emissions today, warming would continue due to what we've already emitted. It just wouldn't be as bad as it will be if we keep doing what we're doing. A better question then is probably, 'What can I do that will have an impact?' My honest thoughts on that are:

• this is a global problem and a classic tragedy of the commons; individuals cannot change much, but leaders can; base your vote on this...do not vote for anyone who lies about this unless all options do, then vote for the option whose lies are least egregious...this is the biggest impact most individuals can have

• educate the people around you so that they do the same; shut down the people around you who lie about this and limit their influence on others as much as you can

• try not to have children, and if you do, try not to have too many

That's basically it...things like an individual installing solar panels on his roof don't really matter. There are some societal things we can push for that have great benefits at a low cost like increased telecommuting, increased access to birth control, incentives for increasing building energy efficiency, and so on, but those are hard to make progress on at the individual level.

Another question you might have instead is, 'How can I prepare for it?' I've created a large number of tools and visualizations comparing cities. My gut is to move to a city that should fare reasonably well. I'll try to start putting together city profiles and give more detailed advice on this, but a really crude summary is:

target

• large source of freshwater that is not snowpack or glaciers

• cool temperatures

• not coastal

• not near an area likely to collapse

• stable and somewhat self-sufficient country

• not located on permafrost

• not likely to experience a catastrophic loss of rainfall

• not a massive wildfire risk

• not right on the threshold of getting tropical diseases

Combining those, you get a few obvious places that seem nice and a few obvious places to avoid. I know the US better than everywhere else so I'm biased towards it, but:

probably good places

• great lakes region (both US and Canada)

• appalachian region

• Pacific NW

• northern Europe

• central Europe

• UK

• southern South America

probably bad places

• anything equatorial

• western/southwestern US; basically anything west of the line from the Texas/Louisiana border to the Kansas/Nebraska border

• Middle East

• anywhere that is already uncomfortably/dangerously hot sometimes

• southern Europe

• Central and SE Asia

• Peru (i.e., dry, glacial melt areas)

• southern Florida and Louisiana; anywhere with sunny-day flooding really

There was an attempt at making a global scale for this, and it can be found here.

Is there really no hope?

There is some tiny chance that we win the lottery. Examples of extremely unlikely things that are still technically feasible are:

• we solve fusion and rapidly roll that out

• we find some very cheap way to pull carbon out of the air and store it permanently; keep in mind that the carbon got there in the first place from energy production and it takes more to remove it, so we're talking undoing the past 150 years of energy production while still providing new energy for ourselves; good summary here and an example of an unusual idea that shows a bit of promise is here

• solar and wind become insanely cheap, we can get it without emissions-heavy mining, we get massive breakthroughs in battery technology, and we opt to shut down fossil fuel plants and replace them with this + all switch to electric vehicles powered by this; for reference on the scale, replacing all US power plants with solar means enough solar cells to cover roughly all paved surfaces in the US, so try to imagine that for the entire world; note also that's just for power plants, so that wouldn't provide fuel for cars, air travel, etc.

That's basically it. We've bet everything on technology that doesn't exist and scientists have told us we shouldn't bank on. The analogy that I've found myself using often is that our strategy with greenhouse gases is like signing up for a class, skipping all assignments, skipping all tests, and hoping to score a 250/100 on the final to make up for it.

Summary

There's not a realistic path to limiting warming to 1.5 or 2 degrees and the world is not seriously attempting it. There is a realistic path to maybe keeping it under 4 degrees. The problems get worse as temperature rise goes up, so we should try to keep it as low as possible but we should stop lying to ourselves about it. We've already locked in significant problems, including large-scale death, economic losses, and most likely conflicts/collapses. The best thing you can probably do as an individual is elect leaders committed to mitigating this and prepare your family.