Next month the UN will host the 26th conference on climate change, the COP26. At this point the discussion is not so much what the goal should be, it’s how to achieve that goal. The Paris Accords set that goal at limiting global warming to 1.5 C above pre-industrial levels. In order to achieve this outcome goal the consensus is that we need to achieve the primary goal of net zero green house gas (GHG) emissions by 2050. There is considerable disagreement about whether or not net zero by 2050 will achieve the outcome goal of limiting warming to 1.5 C. Some experts think it’s already too late for 1.5 C, and we should be planning on at least 2.0 C and what the world will be like with that much warming.

Either way, there is agreement that we should focus instead on what we can actually do, achieve net zero by 2050, rather than the outcome which we cannot predict with that level of precision. If we agree on this goal, the conversation then shifts to the question of how we can achieve this goal. From one perspective the answer is easy – we need to stop burning fossil fuels, convert those industries with the greatest carbon footprint to produce less CO2, and add some carbon capture to compensate for whatever CO2 emissions we cannot fully get rid of. But that’s like saying – in order to win football games you need to score more points than the other team, mostly through touchdowns and field goals. That’s correct, but doesn’t really give you the information you need. How, exactly, will we achieve these ends?

This is the conversation we should have been focusing on for the last 20 years, rather than dealing with denialists who refuse to accept the scientific reality, or the delay tactics by industry and their paid representatives (i.e. politicians). It’s pretty clear at this point we are never going to convince the deniers (not in this political climate – and I’m sure the comments to this post will adequately demonstrate my point), and industry is going to run out the clock any way they can. The bottom line is that achieving net zero by 2050 will require leaving fossil fuels in the ground, unburned. For the fossil fuel industry this means leaving a lot of money on the table, which is not going to happen simply out of a desire to be good corporate citizens.

There are also two primary ways to address the question of how, one it technical and the other political. The technical question has already been answered, multiple times by multiple groups. Here is a very thorough report from Princeton University researchers, who explicitly limit themselves to the technical questions of how to achieve net zero. They specifically avoid making any recommendations, and only lay out possible pathways, their costs and implications. The political question is perhaps harder, and that is probably going to be the focus of the COP26 meeting. This is what is frustrating for climate activists – we pretty much know exactly what we need to do, and the consequences of failure, but can’t seem to muster the political will to do it.

But let’s summarize the technical question very quickly. If you are interested, I suggest you read or at least skim the entire report. It’s very user friendly, with lots of graphics, and it will give you a good idea of the options. The main sources of GHGs are the electricity sector, the transportation sector, and industry, in roughly equal measure, with the rest coming from agriculture, commercial buildings and residential buildings. The graph above quickly puts it into perspective, and shows why focusing on our personal carbon footprint is pretty insignificant. Only systemic change will make any meaningful impact.

The needed changes (and this is probably not news to anyone at this point) include eliminating fossil fuel from energy production and transportation. This means a huge expansion of wind and solar, an addition of nuclear power plants, and an expansion of the electrical grid. With enough nuclear we would not need that much grid storage, but adding some battery and hydrogen grid storage is one pathway also. Because hydroelectric and geothermal are restricted to certain locations, these options will be limited, but are certainly useful and should be maximized also.

For the transportation sector, the answer is obvious – move away from the internal combustion engine to EVs and hydrogen fuel cells. For passenger cars, EVs seem to have one the race. For larger vehicles there may be a niche for hydrogen. For the airline industry, biofuels are probably the only realistic option. Batteries and hydrogen simply don’t have the energy density needed for jets. We have the technology to do all of this today, and this technology is still steadily improving.

The industrial sector is going to be trickier, because we are still developing low carbon alternatives to the big sources of CO2, such as cement and steel. But there are already possible options on the table. They need to be developed at industrial scales, which itself can be tricky, so this is the biggest technical question remaining. It does not seem, as far as I can tell from following the news, that there are any major breakthrough in agriculture coming. We already know the best practices for limiting CO2 release. We also need to replace fossil fuels as a source of fertilizer. GMOs can play a major role here, such as developing the ability to fix nitrogen. In agriculture we just need to continue incremental improvements, and make sure we prioritize carbon balance.

On the commercial and residential building side, there are some efficiencies to be gained with properly insulating homes, using efficient bulbs and appliances, and using efficient heat pumps for heating.

Even in the best case scenario, there is no way to reduce GHG emissions to zero. We therefore will need some carbon capture to offset what remaining CO2 release there is. The low tech way to do this is to plant trees. This will only get us so far, however, because there is only so much land on which to plant trees. We therefore need to continue to develop industrial-level CO2 capture and storage, but we don’t have this tech yet. We have 20 years or so to develop what we have enough to achieve the industrial scales we need, and that’s entirely plausible.

This is all undeniably a lot of change, and on an unprecedented timescale. No one denies that. If we let market forces alone determine the pace of change, all of the above will happen, just far too slowly to prevent unacceptable outcomes from global warming. If we want to speed up the pace, then it will require investment. The Princeton analysis finds that we (the US) will need to invest $2.5 trillion over the next 10 years if we want to achieve net zero by 2050. That may seem like a lot, but it’s only 250 billion per year (compared to a GDP of about 20 trillion, and total federal budget of 4.4 trillion). Further, this should not be looked on as an expense but rather an investment, like infrastructure.

The same analysis finds that switching off fossil fuels will prevent 200,000 – 300,000 premature deaths from pollution, saving by itself 2-3 trillion dollars. So just the health care and lost productivity savings alone will offset this investment. This investment will also produce a net of 600,000 jobs – that a net, above and beyond and jobs lost. That’s a net benefit to the economy. We haven’t even talked about the savings from reduced global warming, which is in the trillions also.

Even if you are a holdout who rejects the science of global warming, getting entirely off fossil fuels will make the world cleaner, save lives, create jobs, and save money. Geopolitically, it will reduce foreign oil profits that generally go to dictators and bad actors, funding their regimes.

How do we achieve these ends politically? That’s the question. There is pretty widespread agreement that a carbon tax not only will work, it will be necessary (but probably not sufficient by itself). We need to compensate for the massive cost that the fossil fuel industry is externalizing onto society, in order to boost their profits. Even if you are a free market purist, that market needs to fully and fairly account for all costs. This one change – fairly pricing fossil fuels by getting rid of subsidies and accounting for the cost of pollution and carbon, will go a long way to achieving the above goals.

The goal of net zero by 2050 is daunting, both technically and politically. It is possible, however, even plausible. But we need the political will to make the technical changes happen, and that, in the end, will likely be our undoing. Climate activists have a point. Politicians are dithering, when we need crisis level courage and leadership.