Category: Science

New discoveries, the scientific method, and all matters relating to the scientific study of the physical world

Wet bulb temperatures and human death

The many human impacts of climate change are complex and often indirect, like how warmer winters in the mountains affect downstream agriculture. The most direct possible effects — however — have been on display in the brutal heat waves on the west coast, as well as elsewhere in the world.

CNN recently published an editorial by Ban Ki-moon and Patrick Verkooijen on the most direct imaginable way in which increased global temperatures can bring harm upon people:

Sweltering temperatures have become the norm in Jacobabad, a town of around 200,000 inhabitants in Pakistan’s Indus Valley that has become one of the hottest places on earth. Temperatures can top 126 degrees Fahrenheit and air conditioning is scarce, leaving the streets deserted and forcing farmers to till their fields at night.

The city, along with Ras Al Khaimah in the United Arab Emirates, has temporarily crossed the threshold beyond which the human body cannot sweat enough to cool itself down. A “wet bulb” temperature of 35 degrees Celsius (95 degrees Fahrenheit) — which factors both heat and relative humidity — can be fatal after a few hours, even assuming ideal conditions such as unlimited drinking water, inactivity or shade. In practice, the bar for this wet bulb temperature, which is measured by covering a thermometer with a wet cloth, is much lower — as shown by the deadly heat waves in Europe in 2003 that are estimated to have claimed 70,000 lives.

Our most basic biological function and a prerequisite and definition of life is the ability to maintain stable conditions inside the body compatible with the needs of our physiology and biochemistry; homeostasis is the term for maintaining internal conditions, and if you don’t have it you’re literally dead.

We’re already artificially coping with places which are literally unliveable without air conditioning, from scorching cities around the Persian Gulf to Phoenix and Las Vegas, which are also profoundly threatened by the loss of winter snowpack and lost river volume and reliability.

Networked citizen science ecology

Promoted by a recent Economist article on biodiversity and Alie Ward’s podcast on foresting ecology, I am trying out the iNaturalist app.

My outdoor pursuits mostly consist of walking at a steady pace for exercise, so plant and wildlife observations aren’t my priority. Nonetheless, it’s neat to be able to take a break anywhere in the city and use the map in the app to see what people have documented in the neighbourhood.

The biodiversity crisis

The concept of the Anthropocene holds that human beings have made changes of such enormity to the planet that they will be chemically identifiable into the distant future. That includes our changes to the atmosphere and disruption to the climate, as well as the radionuclides generated from nuclear tests, accidents, and power stations.

The human impact will also be identifiable through the vast and uncountable number of species we have driven to extinction, probably chiefly through habitat destruction but also from causes as diverse as industrial fishing and the introduction of endocrine disruptors as pollutants.

How exactly this relates to the crisis of climate change is complex and disputed. Certainly, the impact of our GHG pollution on the climate is one of the drivers of extinction, for instance for species which have shifted northward or uphill in response to rising temperatures and which eventually run out of space, or species that have had their life cycles disrupted away from those they have symbiotic relationships with, like when insects act as pollinators for plants.

Some scholars are highlighting how some climate change solutions could exacerbate the biodiversity crisis. For instance, the pursuit of biofuels as alternatives to fossil fuels may drive further habitat loss as land is converted to energy crops. Others have emphasized simultaneous opportunities to both protect biodiversity and climate stability, notably by setting aside territory for nature that will also continue to retain or draw down potential atmospheric carbon.

Related:

Jimmy Carter and the NRX meltdown cleanup

By [President Jimmy] Carter’s own account, his poor opinion of nuclear power originated in personal experience. In 1952 the future president was a US Navy lieutenant with submarine experience stationed at General Electric in Schenectady, New York, training in nuclear engineering under Hyman Rickover. That December, an experimental Canadian 30-megawatt heavy-water moderated, light-water cooled reactor at Chalk River, Ontario, experienced a runaway reaction, surging to 100 megawatts, exploding and partly melting down. It was the world’s first reactor accident, a consequence of a fundamental design flaw of the kind that would destroy a Soviet reactor at Chernobyl three decades later. Since Carter had clearance to work with nuclear reactors, which were still classified as military secrets, he and twenty-two other cleared navy personnel went to Ontario early in 1953 to help dismantle the ruined machine. Because it was radioactive, the calculated maximum exposure time around the damaged structure itself was only ninety seconds. That exposure would be the equivalent of a worker’s defined annual maximum dose of radiation—in those days, 15 rem (roentgen equivalent man). More than a thousand men and two women, most of them Chalk River staff, would participate in the cleanup.

…

Had he known the long-term outcome of the Chalk River radiation exposures, Carter might have felt friendlier to nuclear power. A thirty-year outcome study, published in 1982, found that lab personnel exposed during the reactor cleanup were “on average living a year or so longer than expected by comparison with the general population of Ontario.” None died of leukemia, a classic disease of serious radiation overexposure. Cancer deaths were below comparable averages among the general population.

Rhodes, Richard. Energy: A Human History. Simon & Schuster, 2018. p. 316, 317

Bitumen producers’ distant, unlikely, and disingenuous promises

In perhaps the ultimate demonstration that ‘net zero’ promises are a delaying tactic meant to preserve the status quo which favours fossil fuel producers, Canadian bitumen sands giants Canadian Natural Resources, Cenovus Energy, Imperial Oil, MEG Energy, and Suncor Energy have formed “an alliance to achieve net-zero greenhouse gas emissions from their operations by 2050.”

When firms that see their futures as continuing to dig up the world’s dirtiest hydrocarbons en masse it becomes clear how ‘ambitious’ promises set in the far future are a tactic to avoid meaningful regulation and lobby for additional subsidies right now. In a world genuinely heading for net zero, there will be no reason to exploit the world’s dirtiest fossil fuels, including coal and the bitumen sands. Furthermore, the idea that ‘net zero’ can apply in this context is fanciful. Using a technology like direct air capture to collect all the emissions associated with extracting, upgrading, and burning oil from the bitumen sands would cost so much that it would undermine any economic rationale for extracting the oil in the first place. Furthermore, the idea that the pollution can just be buried fails to fairly consider the scale at which CO2 would need to be buried. There is simply no comparison between the total amount of carbon pollution we emit and the amount we might plausibly bury given the need for a vast new infrastructure to sequester carbon by the gigatonne, and the fact that this infrastructure would only consume money and energy without producing anything of value except reduced pollution. Rather than keep pounding back whisky in the hope that we can build a machine to clean our blood before we die, we really just need to abolish the practice which is creating these dire risks, namely continued fossil fuel exploitation.

Related:

Health and climate change

I was surprised just now to see that I don’t think I have a general thread on climate change and human health.

I’d say there are at least two big relevant dimensions to it.

First, because fossil fuel use causes so many bad health impacts, phasing out fossil fuels brings major co-benefits in terms of avoiding disease.

Second — whereas people seem to find environmental problems generally abstract and of low salience — people seem to have a much more consistent willingness to prioritize health related items. Thus, emphasizing the health impacts of climate change may help to motivate those presently unmoved or hostile to climate action.

There are certainly other important links, including how climate change will alter the distribution of mosquito-borne and other diseases and of course the intersectional ways in which health connects with public policy, economic justice, race, and global equity.

I did for a while host a Canadian government report on human health and climate change, which the Harper government decided to make available to the public only through the mail on a CD.

Health was also an important part of the case we made for divestment at U of T (PDF page 50 / printed page 44-7).

Related:

CBC on the war against the fossil fuel industry

The CBC has two new podcast episodes related to my research. Front Burner has an episode on the movement to divest from the bitumen sands, which tracks the movement’s progression from church groups to universities to major banks and insurers. It notes that only half as many insurers are willing to cover the industry as before the divestment movement began in 2011/12. The second describes Supran and Oreskes’ new analysis of how ExxonMobil has worked to delay climate action and mislead the public, notably by emphasizing consumer responsibility (like the idea of carbon footprints) to try to avoid regulation.

The International Energy Agency (IEA) on the carbon bubble

The International Energy Agency has released a report on what would be necessary to achieve a ‘net zero‘ global economy by 2050: Net Zero by 2050 A Roadmap for the Global Energy Sector.

Unsurprisingly, it replicates the carbon bubble / stranded assets argument: “The global pathway to net‐zero emissions by 2050 detailed in this report requires all governments to significantly strengthen and then successfully implement their energy and climate policies. Commitments made to date fall far short of what is required by that pathway.”

It also asserts the basic concept of a contraction and convergence framework for global equity in emission reductions: “advanced economies have to reach net zero before emerging markets and developing economies, and assist others in getting there.”

Most encouragingly, it avoids the assumption that massive carbon removal technologies will be deployed, meaning a net zero pledge based around effective fossil fuel abolition:

Net zero means a huge decline in the use of fossil fuels. They fall from almost four‐fifths of total energy supply today to slightly over one‐fifth by 2050. Fossil fuels that remain in 2050 are used in goods where the carbon is embodied in the product such as plastics, in facilities fitted with CCUS, and in sectors where low‐emissions technology options are scarce.

This is naturally an enormous challenge to the companies and governments choosing to pretend that there will be an easy technological fix which reconciles controlling climate change with continued fossil fuel use.

Unsurprisingly, the CBC describes Canadian reactions to the report as “mixed”.