Science – Page 37 – a sibilant intake of breath

Climate and the timing of emissions

Climatologist James Hansen emphatically argues that cumulative emissions are what really matter – how much warming the planet experiences depends on what proportion of the world’s fossil fuels get burned.

One reason for this is the long lifetime of CO2 in the atmosphere, with much of it remaining after thousands of years. That being said, the model simulation I have seen shows concentrations dropping sharply, and then tapering off with time:

It seems like it would be helpful to put together that chart with this one, showing historical and expected CO2 concentration increases:

A combined chart on the same scale would illustrate what would happen to CO2 concentrations if we stopped emitting at some point soon, specifically what the next few decades would look like.

It seems at least logically possible that timing of emissions could matter. Imagine, for instance, that having emissions cross a certain concentration threshold would really matter. If so, spreading out human emissions so that absorption of CO2 by the oceans would keep the concentration below that cap could be quite beneficial.

It seems an important question to sort out, given how the whole BuryCoal project is focused on limiting total human emissions, rather than trying to space them out.

The Pleasure of Finding Things Out

Probably the most problematic thing about writing associated with Richard Feynman is repetition. Both his books and books about him tend to be at least quasi-biographical, and often feature the same stories, examples, explanations, and even bits of writing.

The Pleasure of Finding Things Out certainly suffers from this flaw, at least for those who have read one or two Feynman books before. It includes, for instance, his appendix to the Challenger inquiry report, which also formed a major part of What Do You Care What Other People Think. It also features Feynman’s thoughts on ‘cargo cult science’ which have been reproduced elsewhere.

All that said, the book does contain some interesting materials that do not seem to be widely available elsewhere, particularly on the subject of nanotechnology. Going back to first principles, Feynman considers what lower size limits exist for things like motors, computer processors, and data storage systems. He concludes that there is ‘plenty of room at the bottom’ and thus enormous scope for improving our capabilities in computing and other fields by relying upon very small machinery and techniques like self-assembly.

Torpedoes, Pearl Harbor, and the atomic bomb

One of the most interesting things about Richard Rhodes’ detailed history of the making of the atomic bomb is the way it gives the reader a better sense of context. This is especially true when it comes to things happening in very different places and spheres of life. It would take an unusual facility with dates, for instance, to realize how the timeline of research into the abstract physical questions about the nature of atoms lined up with political, economic, and military developments.

One grim but interesting example comes from the end of Chapter 12. In November 1941, Franklin Delano Roosevelt had just committed the United States to the serious pursuit of an atomic bomb based upon enriched uranium (U235) and three methods for producing the substance were to be attempted: gaseous diffusion, electromagnetic separation, and centrifuges (the approach Iran is using now). On December 7th of that year, the Japanese Navy attacked the American base at Pearl Harbor.

Rhodes describes how Japanese research into atomic weapons began with the personal research of the director of the Aviation Technology Research Institute of the Imperial Japanese Army – Takeo Yasuda – in 1938, and expanded into a full report on the possible consequences of nuclear fission in April 1940. Rhodes also describes a somewhat grim coincidence involving Japan, the United States, and atomic weapons. He describes how ordinary torpedoes would not have worked for the Pearl Harbor attack, because the water was insufficiently deep. As such, the torpedoes used had to be modified with a stabilizer fin and produced in sufficient quantity for the pre-emptive strike to be successful:

Only thirty of the modified weapons could be promised by October 15, another fifty by the end of the month and the last hundred on November 30, after the task force was scheduled to sail.

The manufacturer did better. Realizing the weapons were vital to a secret program of unprecedented importance, manager Yukiro Fukuda bent company rules, drove his lathe and assembly crews overtime and delivered the last of the 180 specially modified torpedoes by November 17. Mitsubishi Munitions contributed decisively to the success of the first massive surprise blow of the Pacific War by the patriotic effort of its torpedo factory in Kyushu, the southernmost Japanese island, three miles up the Urakami River from the bay in the old port city of Nagasaki. (p.393 paperback)

That attack – launched partly in response to the American embargo of aviation fuel, steel, and iron going into Japan – sank, capsized, or damaged eight battleships, three light cruisers, three destroyers, and four other ships. The two waves also destroyed or damaged 292 aircraft, and killed 2,403 Americans, while wounding another 1,178. More than 1,000 people were killed just in the sinking of the U.S.S Arizona.

CO2 is plant food

One of the many things that falls into the category of ‘things that climate change deniers say that are true, but deeply misleading’ is the claim that carbon dioxide (C02) is ‘plant food’ and thus beneficial to the planet.

This video does a nice job of smashing that argument.

Ironically, in the very long term, life on Earth actually is imperiled by the possibility of insufficient CO2, though not on a timescale that human beings need to worry about now. A billion years from now, it could be a problem.

Climate change ‘winners’

Today’s Globe and Mail makes a good point about the ongoing Russian heatwave and wildfires, namely that they are a partial counter to the argument that northern countries like Russia and Canada would benefit from a warmer climate:

Russia’s summer heat wave has dimmed prospects that northern countries will “win” from climate change thanks to factors such as longer crop-growing seasons or fewer deaths from winter cold, experts say.

Canada, Nordic countries and Russia have been portrayed as among a lucky few chilly nations where moderate climate change will mean net benefits such as lower winter heating bills, more forest and crop growth and perhaps more summer tourism.

…

“It’s not a matter of a benign shift to a longer growing season” for northern nations, said [Kevin Trenberth, head of climate analysis at the U.S. National Center for Atmospheric Research in Boulder, Colorado]. Russia’s heat wave doubled death rates in Moscow, wrecked a quarter of Russia’s grain crop and may cut $14-billion from gross domestic product.

It is certainly odd to see climate change deniers who – in the course of the same speech or article – will claim that climate change isn’t happening at all, that it is pefectly natural, that it is actually going to be beneficial, and that it is all China’s fault for building too many coal plants.

The fact is, all of our infrastructure was designed for the kind of climatic conditions human civilization emerged in. While it is certainly likely that a few people will benefit from climate change, for the most part it will mean that roads, buildings, agricultural systems, and so on are increasingly poorly suited to the area where they are situated.

I wrote before about climate change and Australian brushfires.

Pondering mosquito-cide

Generally speaking, it seems like a bad thing when human beings eliminate an entire species. That said, it is usually done by accident, as a consequence of habitat destruction and pollution. To a considerable extent, we should probably scale back those harmful activities, and think about backing up some DNA in the meantime.

In at least one case – the eradication of smallpox – the destruction of a species seems unambiguously excellent. Indeed, it is a shame we didn’t manage to finish the job, and that Russia made such huge quantities of smallpox as a weapon. Mosquitoes are another candidate for a species we could wipe out without guilt, especially since ecologists are arguing that they don’t serve a major ecological role.

The ethical question is: if it were practical to do so, should humanity exterminate all mosquitoes?

Energy in wasted food

Here’s a sobering fact: there is apparently more energy in wasted food in the US than in the Gulf of Mexico:

Americans aren’t, technically, eating an average of 3774 calories per day. This figure is calculated by looking at food produced, divided by the number of Americans. It assumes we’re eating all that, but, in reality, according to environmental scientist Gidon Eshel we really only eat about 2800 calories per day. That whopping 3774 includes both what we eat—and what we waste…

We use a lot of energy producing, transporting, processing, storing and cooking food we don’t eat. About 2150 trillion kilojoules worth a year, according to a recent study. That’s more kilojoules than the United States could produce in biofuels. And it’s more than we already produce in all the oil and gas extracted annually from the Gulf of Mexico.

This is suggestive for several reasons. Firstly, it reinforces the point that the United States cannot drill the way out of their oil addiction problems – domestic oil supplies just aren’t adequate to make much of a difference. Secondly, it is a reminder of how energy is both a critical and a largely hidden part of our society. Thirdly, it shows how people respond to economic incentives – such as the cheapness of food – by acting frugally or wastefully in response. Fourthly, it shows yet another area where conservation can help us, as we make the shift to sustainable and zero-carbon forms of energy production and use.

Cancer and the neutron

I think of cancer, and radiation therapy for it, as modern phenomena. It was surprising, then, to learn that radon ‘seeds’ were being used for radiation therapy of cancer in 1929 – before the neutron had even been discovered. Indeed, polonium extracted from depleted seeds from Baltimore’s Kelly Hospital provided James Chadwick with the neutron source for the experiment that confirmed their existence. Neutrons are critical for inducing the fission of atoms, whether in bombs or power plants, because they are not repelled by the electric fields around atoms.

A detailed account of the experiment is in chapter 6 of Richard Rhodes’ The Making of the Atomic Bomb.

Sea ice extent and volume

Over at RealClimate, Dirk Notz has written a good post about climate change and Arctic sea ice. In it, he highlights the importance of aggregated data, pointing out how, despite variations in regional weather, the mean temperature of the entire globe during the last 12 months is the highest it has been since the beginning of the records 130 years ago.

The figure that is most watched, when it comes to Arctic sea ice, is the extent of ocean covered by ice. This isn’t a spectacularly good measure, however, as Notz explains:

The reason for this is mostly that sea ice in the Arctic has become very thin. Hence, in contrast to the much thicker ice of past decades, the ice now reacts very quickly and very sensitively to the weather patterns that are predominant during a certain summer. This currently limits the predictability of sea-ice extent significantly.

A better measure is ice volume, which has been falling consistently as the planet warms.

Ten indicators from the Met Office

One reason we can have a lot of confidence about the basic science of climate change – that the world is warming, because of people, in ways that could be harmful to humanity – is because there are numerous independent indicators showing the same trends. A new report from the Met Office in the United Kingdom highlights this, pointing to ten distinct indicators that all show the planet warming:

Rising air temperature over land
Rising sea-surface temperature
Rising marine air temperature
Rising sea-level
Rising ocean heat
Rising humidity
Rising tropospheric temperature in the ‘active-weather’ layer of the atmosphere closest to the Earth’s surface
Declining arctic sea-ice
Declining glaciers
Declining spring snow cover in the northern hemisphere

Deke Arndt, who co-edited the report, explained that: “The records come from many institutions worldwide. They use data collected from diverse sources, including satellites, weather balloons, weather stations, ships, buoys, and field surveys. These independently produced lines of evidence all point to the same conclusion: our planet is warming.”

None of this is new, really, but there is value in re-expressing it and stressing how the different indicators reinforce one another. Climate change deniers often fixate on details, raising doubts about a single measure and then suggesting that this calls into question the whole edifice of climate science. What work like this Met Office report indicates is how climate scientists are approaching the problem in a way that reduces the danger of such dangerous extrapolations.

Of course, that means climate change is something we really do need to worry about, and which we ought to be taking much more action about.