Climate Change and the Trump Effect

How much additional risk do we face?

We faced a dire climate situation when voters cast their ballots for president in November 2024, and it is even more dire today, but how much more? With an issue this cataclysmic and complicated, there is a temptation to make sweeping statements (we’re all screwed!), but it’s better to take a deep breath and examine the specifics. In this piece I will try to assess the likely damage the Trump/Musk regime will inflict on climate policy, its effect on the risk we face, and implications for future activism. I’ll take a brief look at each aspect of the current policy turnaround and then put them together in the context of what it will take to avoid the worst case climate outcomes.

First though, what constitutes a “climate catastrophe”, compared to, say, a nasty but manageable future? While the line separating manageable from unmanageable outcomes is fuzzy, there is one risk that towers over all the others, the possibility that our excessive releases of greenhouse gases into the atmosphere could trigger an amplifying set of feedback processes, in which too much heat sets in motion planetary responses that trap even more heat, and so on. Candidates for such processes include releases of methane from permafrost and marine deposits, destabilization of forests on a global scale, reductions in ice cover that cause less solar radiation to be reflected back into space and increases in heat-trapping cloud formations. Singly they are scary, but each can potentially spur the others. A feedback cascade of this sort is what could produce the unlivable Earth scenario.

It would be helpful if we knew the exact boundary we dare not cross in order to prevent this from happening, but we don’t. It is possible, although very unlikely, that we have already crossed it, but the best way to think about the problem is that every fraction of a degree of warming increases the feedback risk. As a matter of convention, climate scientists draw their own line at two degrees Celsius—not that a lesser level of warming, such as the 1.5 degrees we are already experiencing, is benign, but somewhere beyond two degrees the feedback risks become unacceptable. A further consideration is that a two degree increase over pre-industrial (mid-nineteenth century) temperature averages is probably the most stringent feasible target we can hold ourselves to; less warm would be better, but it’s probably out of reach. Keeping the planet within that limit is the standard against which policies in place before the Trump ascendancy, and their shredding today, should be evaluated. Here’s the scorecard:

1. Exiting the Paris Agreement. In 2015 the United States, along with nearly every other country, signed onto a broad agreement that set climate goals and obligated countries to report their plans to meet them. This was widely seen at the time as a big step forward, and in many ways it was. Above all, it enshrined a prudent pair of targets, 1.5 degrees warming if possible but in any case under two degrees, that reflect scientific understanding of what is required to stave off catastrophic impacts. While obligating countries to issue reports falls short of mandating them to take specific steps to meet these goals, it’s a reasonable starting point. The Agreement, moreover, committed wealthier countries like the U.S. to contribute to a fund that could be used to moderate the impacts of unavoidable climate change on less developed countries. Trump’s withdrawal from the Paris Agreement, announced the day of his inauguration, undermines all three of these achievements, although the extent of backpedaling on the part of other signatories is unclear at this point. It is doubtful this action will alter the international consensus (where “international” means everyone but us) on holding warming to a maximum of two degrees, and countries will most likely continue to make various pledges and report the measures they intend to take to fulfill them. The global adaptation fund established under the agreement will be diminished without U.S. support, but it was already grossly underfunded, so the Trump effect will be less than it should be.

But the Paris Agreement had serious drawbacks as well, and the U.S. withdrawal may give us an opportunity to reconsider them. The biggest step backward was that it framed climate mitigation in terms of achieving “net zero” emissions at some point in the future, roughly mid-century. This quickly became the way not only governments but also activists and researchers talked about policy: how would this or that measure help us get to net zero? But there are two immense problems with this framing. First, there is immense wriggle room packed into that three letter word “net”. The implication is not that we will have zero carbon emissions in the target year, since that is impossible, but that we will employ methods that remove carbon from the atmosphere to offset whatever emissions remain. Obviously, a lot depends on what assumptions you make about future “negative emission” technologies. In practice, the assumptions have been extremely optimistic, allowing authorities to invoke net zero ambitions even while they have no intention of eliminating most use of fossil fuels. In other words, saying you are on the road to net zero has no particular content, because it implicitly depends on forecasts of negative emissions that can be expanded to whatever level is convenient. Second, net zero is a condition that will come to pass decades from now and is therefore useless in assessing whether current emissions are consistent with the Paris targets. And it’s worse than this, because, for carbon dioxide, by far the most important greenhouse gas, the warming effect is cumulative, so every year’s emissions matter equally, not just the emissions in 2050 or whenever. Under a net zero framing, there is essentially no accountability in the present—no way to determine whether current action is insufficient and by how much. Rethinking the Paris Agreement is an unavoidable step in the process of freeing ourselves from the net zero frame.

2. Reversing government support for clean energy. Trump has taken action to overturn several Biden-era initiatives whose purpose was to accelerate an energy transition away from fossil fuels. This includes scrapping EV chargers at federal facilities, making it harder for wind and solar projects to get regulatory approval, relaxing fuel efficiency standards, scaling back support for mass transit, and most visibly, canceling subsidies for battery production, grid upgrades and other programs under the Inflation Reduction Act. These are obviously not helpful, but how much they set back the cause of climate mitigation is hard to say. In part this is because the Trump reversals are still new, and we don’t know yet what their scope will be. One day Musk taketh, the next he giveth back—then taketh again. That is particularly true of the IRA, where actions by Trump to slow down, minimize or cancel investments amount to about $7.5 billion of over $300 billion in projects somewhere in the IRA pipeline. Of course, Trumpian attacks on clean energy are especially hard to evaluate in the absence of a meaningful benchmark; if we don’t know how much climate progress would be “enough”, we don’t know how much further Trump is taking us from this standard.

There is a deeper problem with assessing the Trump effect: most of the Biden agenda was about promoting green energy, but there is no particular relationship between how much green energy we produce and how much carbon we emit into the atmosphere. Yes, they are negatively related, but not on a one-to-one basis, nor on any other basis that stays constant over time. To put it differently, we live in a world of increasing energy use which allows more clean energy to coexist with more of the dirty sort. Obviously, expanding the supply of noncarbon energy sources and the infrastructure to match it to demand makes it easier to cut back on coal, oil and gas—but only if we actually cut back on them, which we have very few policies to do. Later I will make this point quantitatively with an eye toward the change in strategy we will need to minimize the risk of a climate catastrophe.

3. Shutting down climate research and critical data sources. There are several related issues here: the cessation of federal funding, through NOAA, the EPA, the NSF and other agencies, for climate research, the closure of federal agencies that conduct such research or collect data that researchers need, and the shuttering or censoring of data portals that make existing climate data available to researchers and the general public. It is unclear at this point whether all of these activities will be curtailed, only some, or only to some extent. Of course, the Trump/Musk attack against data and scientific analysis is shocking no matter how far it extends. It is extraordinary that we are witnessing an effort to obstruct scientific understanding of perhaps the most important question of our time. I can’t think of a precedent for such hostility to the organized use of evidence and reasoning.

That said, we don’t know how severe the impacts will be. Some datasets will be disrupted, but others are mirrored by other governmental and nongovernmental institutions. Some funding cuts will be offset by increases from other sources, and climate research is global, with the majority of it conducted by non-US citizens and financed by non-US entities. Of course, research is not so abundant that the loss of a portion of it won’t be felt, but how much will be lost and how large a difference it will make remains to be seen. Until now, no one has thought to ask what proportion of research is funded directly or indirectly by the U.S. government, so we don’t know the extent to which other countries can plug the hole. The silver lining on this cloud, such as it is, is that policy already lags research by a large amount; what we already know is sufficient to justify and shape much more ambitious actions than governments have thus far taken. But if there are even darker clouds on the horizon, we surely want to see them as soon as possible.

4. Corporate retreat from voluntary climate commitments. Corporations ostentatiously respond to the political climate. When it appeared that authorities might implement climate policies that would impinge on their bottom line, they professed to be converts to the green cause and, with ample publicity, announced their voluntary actions. Now that the tide has turned in the opposite direction, strongly with Trump but subtly with the EU, corporations are pulling back. For instance, just recently BP (British Petroleum) announced a “reset” to their investment strategy, ramping up oil and gas development and ending initiatives in wind and solar.

How much will this reversal set us back? That depends on how beneficial corporate voluntarism has been in the first place. With BP and its sister fossil fuel producers, it is clear that voluntarism has done nothing to restrict supply; OPEC+ is the venue for that, and they have kept restriction to a minimum, as reflected in prices. Moreover, it is unclear why fossil fuel companies should be the ones to invest in noncarbon energy, since they have no particular expertise to bring to it. (We have financial intermediaries like banks for steering the profits from one sector to investments in another.) For an evaluation of rollback across the corporate world, we would need to know what each individual company had earlier promised and how much they are now revising, a monumental task. Fortunately, there is a more or less standardized method for firms to convey environmental commitment, their ratings on environmental, social and governance (ESG) criteria, and a recent analysis found no ESG effect on carbon emissions. If this is indicative of the larger set of environmental commitments made by firms, it suggests we have lost little by the rollback because there was little to lose.

Putting all of this together, how distraught should we be? The U.S. is just one of several countries that our climate future will depend on, and the new stance of the federal government removes only one portion of its private/public involvement. There are still foundations, NGOs, state and local governments and private citizens who can step up to absorb some of these cuts. But the ultimate assessment depends on how effective we think US policy was before the advent of Trump II.

This is an immense topic with more complication than we can address here, but a rough estimate is possible. The critical point to bear in mind is that, while existing targets aiming at net zero in some distant year are useless for benchmarking purposes, a simple alternative is available, the rate of carbon emission reduction needed to stay within a reasonable warming limit like two degrees Celsius. Leaving the technical details aside, most warming is attributable to the accumulation of carbon dioxide in the atmosphere, and researchers have estimated the total amount of CO2 at which a given warming goal will be breached with a given likelihood. Subtract the amount already emitted from the estimated total and you have the remaining carbon budget. Based on this budget and the level of current emissions we can then calculate the rate of emission reduction that keeps us on target. For a 2/3 chance of keeping warming at two degrees that rate comes to about 4%; for a 90% chance of no more than two degrees it’s about 7.5%. These are for the world as a whole; wealthier countries like the US have to cut more so that others, with more pressing needs for economic growth and less responsibility for past emissions, can cut less. For convenience, I like to think of this as requiring a 50% increase in the required rate of reduction, i.e. 6% or 11.25%. (These are predicated on assumptions about reductions in other greenhouse gases and will have to be adjusted if they aren’t met; they also depend on expectations regarding the effect that further warming will have on earth systems, which is why they are expressed as likelihoods and not certainties.)

Armed with that, we can look at the recent US and global record. Here are carbon dioxide emissions over the past ten years, nationally and globally:

CO2 emissions in billions of metric tonnes

Source: Our World in Data

In the US case, we see a fluctuating but overall modest decline in CO2 emissions, mainly due to the replacement of coal by (mostly) natural gas in energy production. The average year-to-year decline is just over 1%, well below the 6% benchmark I suggest. But warming is determined at the global level, and here the news is unpleasant: CO2 emissions have been rising at an average rate of 1.5% a year. Despite all the fanfare surrounding international meetings and proclamations of the coming net zero utopia, we are steadily advancing toward a climate nightmare. (Note that the one-off reduction in the Covid year 2020 showed that sufficient cuts are possible. Of course, that was accompanied by much economic dislocation; ideally a planned cutback could be carried out more sustainably.)

Now consider the energy context. Here is total energy consumption for the US and the world, measured in petawatts. (Don’t worry about the units; it’s the trend that matters.)

Energy consumption in petawatts

Source: Our World in Data

As we can see, US energy use has remained roughly constant over this period, although there is an expectation that large, energy-intensive server farms to furnish AI and related technologies will put us once again on an upward energy path. Meanwhile, the global trend has been unmistakably on the upswing, expanding by more than a third over the period. As long as this remains the case, increased supplies of noncarbon energy will do little to shield us from frightening climate scenarios.

The reason for reviewing all this is to make it clear that, terrible as they are, the Trump/Musk climate reversals are not transforming a proactive world into a sleepwalking one; we have been sleepwalking all along. The good news is that the bad news is only slightly more bad. But looking ahead, the key lesson is that it would make no sense to respond to these rollbacks by demanding a restoration of climate policy as of 2024. An entirely different approach is needed, one that takes direct action to reduce carbon emissions in accordance with the benchmarks sketched above, along with other measures that smooth the path by ramping up clean energy production and greater end use efficiency. As I’ve argued elsewhere, the most effective way to do that would be to institute a system of permits for bringing carbon fuels into the economy (extracting or importing), capping the number of permits allowed, auctioning them off (making users pay), and rebating the revenue back to the people so we can spend our money on other things. It may not make billionaires smile like tax cuts, deregulation and disemboweling the government seem to do, but, given the stakes, we’ll have to find the democratic resources to pull it off.