Debunking Vivek Ramaswamy's climate claims

I’ve been getting emails from reporters asking for comments on the climate claims of Vivek Ramaswamy during a GOP debate and subsequent media appearances. While I hate to give oxygen to bad-faith climate misinformation, it seems like this is a subject that people are interested in.

tl;dr: While Ramaswamy asserts his claims are “hard facts,” a closer examination reveals they are carefully constructed to be (generally) accurate but misleading. Here are four of Ramaswamy's key points:

1. “I can offer clear evidence that the number of climate disaster related deaths is down by 98%”

Regardless of the accuracy of these numbers, this framing is wrong. The decline in deaths is not due to fossil fuels, but due to the availability of cheap energy. Fossil fuels did, of course, provide the cheap energy, and for that we should be thankful.

So a tip of the cap to fossil fuels. But the climate debate is not about the past, but about the future: what is the best energy source for the coming century?

Fossil fuels come with a litany of enormous negative impacts. First and foremost, the burning of fossil fuels is a primary driver of climate change, which in turn leads to escalating global temperatures, sea-level rise, changes in precipitation, etc. The impacts of this are much more than “deaths from disasters”. Ask someone in Florida who’s trying to get home owners insurance.

If you do want to focus on deaths from fossil fuels, air pollution resulting from the burning of fossil fuels has been estimated to be responsible for one in five deaths worldwide. And the health impacts go far beyond mortality: David Wallace-Wells has thoroughly documented the range of health impacts that accompany air pollution.

In addition to these environmental and health repercussions, the geopolitics of fossil fuel resources lead to political instability. Resource-rich regions become flashpoints for conflict — don’t forget that the U.S. invaded Kuwait and Iraq to maintain the integrity of the oil supply.

It also gives nations with significant fossil fuel reserves the ability to cause international chaos, as evident in cases like Russia and the Ukrainian war or Saudi Arabian influence in our elections. Additionally, the boom-and-bust nature of fossil fuel markets can lead to economic instability, disproportionately affecting communities that are heavily reliant on extraction industries.

The alternative is climate-safe, renewable energy, which is now as cheap as fossil fuels and don’t have nearly as many disadvantages (although they do have some).

So in reply to Ramaswamy’s statement about decreased mortality from disasters, I say “so what?” We need to look at all of the impacts of our energy sources and ask the question what energy sources should be the foundation of the future?

2. “Eight times as many people die of cold temperatures than die of warm ones.”

The assertion is statistically accurate, but the implication — that global warming will therefore benefit humanity by reducing temperature-related mortality — is much less clear. Warming does reduce cold-related mortality while increasing heat-related mortality. The overall effect is the net of these two factors.

The net impact depends primarily on three factors: how much warming occurs, how well we adapt to increasing temperatures, and the region you’re looking at. Aggregating over the entire planet, we see an increase in global temperature-related mortality:

Projected mortality effects of climate change. In Panel A, each line represents mortality under difference scenarios of economic growth and adaptation. Panel B shows the total mortality effects of climate change (equivalent to the solid line in Panel A), as well as the mean and interquartile range. The boxplots show the distribution of mortality effects of climate change in 2100 under both RCPs. From Carleton et al. 2022

Even if it turns out that there is little change in total temperature-related mortality, it’s a balance between regions where mortality is increasing and regions where it’s decreasing. In other words, we will see a shift of mortality from richer to poorer regions that are not well adapted to heat.

The map indicates estimates of the mortality effects of climate change, measured in units of deaths per 100,000 population, in 2100. Estimates come from a model accounting for the benefits of adaptation and income growth; density plots for select regions indicate the full distribution of estimated effects across all Monte Carlo simulations. From Carleton et al. 2022.

So in reply to Ramaswamy’s statement about more cold-related than heat-related mortality, I again say “so what?” There’s basically no good news in the projections of future mortality.

3. “The Earth is covered by more green surface area today than it was half a century or a century ago because carbon dioxide is plant food”

Ramaswamy highlights that the Earth is greening, attributing this to carbon dioxide's role as “plant food.” This claim is once again designed to cast doubt on the seriousness of the impacts of climate change.

While it’s true that increasing CO2 does generally stimulate plant growth, that doesn’t mean that the plants humans rely on will benefit from it. Corn, for example, the most produced crop in the world, derives little benefit from increased levels of CO2. In addition, temperature increases and changes in precipitation that accompany the increases in CO2 will also have big and in many cases negative impacts on agriculture.

I previously posted an interview with David Lobell, one of the world’s experts on climate change and agriculture, where we had this exchange:

Me: So are you worried about the climate impacts on agriculture?
David Lobell: Yes. I think the evidence is very clear that, on net, the changes going on in the atmosphere, including all the climate changes, are a risk to a lot of major production systems and to a lot of food insecure areas. So there's definitely a reason that we that we continue to work on how to adapt to these changes.

4. “Carbon dioxide as a percentage of the atmosphere is still at a relative low in human history”

Unlike the previous claims, this one is just plain wrong. “Human history” goes back maybe a few hundred thousand years. Over that time, atmospheric CO2 levels have hovered between 180 and 280 ppm. Since 1800, the industrial revolution, fueled primarily by fossil fuel combustion, has pushed those levels to around 420 ppm, unprecedented in human history.

CO2 over the past 400,000 years

If you look at the entire Earth's history, carbon dioxide has indeed been much higher than today.  In the Eocene, for example, about 50 million years ago, carbon dioxide was much higher and the climate was correspondingly much hotter. There was little permanent ice anywhere and sea level was 250 feet higher than it is today. There
were alligators in the Arctic and palm trees in Wyoming and, in the tropics, the Eocene was hot enough to support nightmare-sized snakes.

Conclusion

If you see a pattern here, you’re not wrong. Ramaswamy’s claims generally contain elements of truth, but they are nevertheless misleading . This is a savvy political strategy — throw red meat to the base — and it has been quite successful in getting him attention in a crowded campaign field. But make no mistake: future generations are relying on us to not get distracted by these shiny arguments.