Critical Exponent

You can look up studies on the genetics of homosexuality using the OMIM website. What jumps out of this collection of studies is that, for males, the genetic link appears to come through the mother (X chromosome) and that boys with older siblings are more likely to be gay. Interesting.

I learned about this through the NY Times Tierney lab. As seems to be the case every time I bother to look (is it sampling bias?), reader comments on newspaper blogs degenerate into the tangential, irrelevant, and specious. Sigh.

Remember Jim Hansen, the director of NASA’s Goddard Institute for Space Studies? He was the one that the Bush administration tried to silence after he gave a public warning that the current rate of fossil fuel use will make the earth into “a different planet.”

Hansen’s work is the subject of an article in Technology Review that explains how danegrously close we are to the point of no return. Look at this graph. It appears that every 100,000 years, small oscillations in the earth’s orbit cause minute changes in the amount of, and larger changes in the distribution of, sunlight on the earth. These changes caused natural fluctuactions in carbon dioxide levels, which in turn led to temperature fluctuations on the order of 5°C, enough to change ocean levels by 100 meters. It appears we are in the middle of such a natural fluctuation right now.

Now look at the very right edge of the graph. Carbon dioxide levels have skyrocketed since the start of the Industrial Revolution. This is clearly not part of any natural cycle– and is a harbinger of dire consequences:

Owing to greenhouse changes we have already incurred, Hansen told his audience in San Francisco, Earth’s temperature will rise about 0.5 ºC in the next 50 years even if we stop burning fossil fuels today. We’re on a slippery slope: we could cross a threshold that leads to a drastically different planet, half a century before knowing that we’ve done so. Hansen believes we are horrifyingly close to such a threshold, and that we will cross it if we don’t change our greenhouse ways within the next few years.

Earth is now passing upward through the highest temperatures of the past 12,000 years, and the half a degree that is already in the pipeline will bring temperatures within half a degree of the high points they have reached only a few times in the past two million years. During a warm period about 120,000 years ago, for example, sea levels were probably five or six meters higher than they are today.

Running future emissions scenarios on a GISS computer model, Hansen finds that if we remain on the path he calls “business as usual,” temperatures will rise between two and three degrees this century, making Earth as warm as it was about three million years ago, when the seas were between 15 and 35 meters higher than they are today. There go many major cities and the dwellings of about half a billion people.

The current issue of Technology Review is dedicated to the climate crisis and how the technologies exist to slow down human-induced climate change: time is running out, but it’s not too late yet.

Finally, to the skeptics who refuse to accept these conclusions and are happy to proceed with business as usual, I offer this: No one debates that modern technological advances, and in particular industrialization, change the environment (think strip mining, deforestation) and pollute the atmosphere (think smokestacks) and the oceans (think chemical effluvia). Surely all those byproducts will have some sort of effect, don’t you think? It’s not impossible that the scientists who have spent countless careers studying these phenomena could be wrong, but are you willing to take the chance that maybe, just maybe, they’re right? If we as a species clean up after ourselves and leave the natural world no worse than we found it, then, and only then, can we rest assured that climate fluctuations are not due to our activities.

I think the world map in a century or two will look very different:

The Antarctic ice sheet is losing as much as 36 cubic miles of ice a year in a trend that scientists link to global warming, according to a new paper that provides the first evidence that the sheet’s total mass is shrinking significantly….

It is one of a slew of scientific papers in recent weeks that have sought to gauge the impact of climate change on the world’s oceans and lakes. Just last month two researchers reported that Greenland’s glaciers are melting into the sea twice as fast as previously believed, and a separate paper in Science today predicts that by the end of this century lakes and streams on one-fourth of the African continent could be drying up because of higher temperatures.

Sometimes I despair when I think of where this country is headed. Here are two of the latest salvos in the culture wars:

• A Pennsylvania school district voted to end the International Baccalaureate program. The reasons cited by various people include claims that it is too liberal, part of an international conspiracy, and too expensive. As an IB alum, I can vouch for the fact that the goal and focus of the program is to teach students to think critically, to prove mastery of advanced academic skills via an internatially-certified standard, and to expose students to other cultures as well as their own.These last two are particularly valuable in today’s global economy and society. Cutting the program shortchanges the students, contributes to America’s decline in science, technology, and culture, and reveals how tenuous the dogmatists’ positions are, if they feel they must shelter students from other points of view lest they make up their own minds.

• The New York Times reports on many evangelicals who signed an anti-evolution petition; these include a few scientists, though apparently no biologists. What is wrong with people? Evolution remains the best scientific theory for the origins of life as we know it today: its mechanism has been observed in microcosm, and it is simple, in that it does not posit unobserved and extraneous external agents such as a designer or aliens. All the opposition to evolution seems to come from some combination of faith (”it contradicts my religious texts”) or lack of imagination (”I can’t see how evolution could possibly give rise to the large differences among species”). Neither of those is a valid reason to overturn or ignore a scientifc theory. Once again, based on the observed evidence, Darwin’s theory remains the best (simplest, most compact, consistent with observation, micro-reproducible, and falsifiable) explanation for the origins of life. It’s certainly your right to believe what you want to believe, whether it’s science, faith, both, or neither, but please don’t claim that evolution is on a shaky scientific footing, because it’s not.

No one knows for sure, but it seems likely that irreversible climate change could happen within our lifetimes. Humans have a great capacity for denial, though, and we’d much rather focus on present profits when we can and urgent crises when we must rather than long-term savings, stability, or sustainability. Exhibit A is the Bush administration:

Some scientists, including President Bush’s chief science adviser, John H. Marburger III, emphasize there is still much uncertainty about when abrupt global warming might occur.

“There’s no agreement on what it is that constitutes a dangerous climate change,” said Marburger, adding that the U.S. government spends $2 billion a year on researching this and other climate change questions. “We know things like this are possible, but we don’t have enough information to quantify the level of risk.”

Fair enough, but digging our heads in the sand and withdrawing from the Kyoto protocols is not the way to prepare for a possible worst-case scenario that, if realized, would be catastrophic.

Oh, and you’ve got to love this:

When [James E. Hansen, who directs NASA's Goddard Institute of Space Studies] posted data on the Internet in the fall suggesting that 2005 could be the warmest year on record, NASA officials ordered Hansen to withdraw the information because he had not had it screened by the administration in advance, according to a Goddard scientist who spoke on the condition of anonymity. More recently, NASA officials tried to discourage a reporter from interviewing Hansen for this article and later insisted he could speak on the record only if an agency spokeswoman listened in on the conversation.

“They’re trying to control what’s getting out to the public,” Hansen said, adding that many of his colleagues are afraid to talk about the issue. “They’re not willing to say much, because they’ve been pressured and they’re afraid they’ll get into trouble.”

But Mary L. Cleave, deputy associate administrator for NASA’s Office of Earth Science, said the agency insists on monitoring interviews with scientists to ensure they are not misquoted.

“People could see it as a constraint,” Cleave said. “As a manager, I might see it as protection.”

Nice. “We’re not going to do anything about global warming until we know it’s really happening (and we’ll tell you when that is), but by golly we’ll make sure to ‘protect’ what our scientists say.”

Do you ever feel we’re taking our planet to hell in a handbasket?

The out-going president of the Royal Society warns of fundamentalism hampering our ability to deal with scientific challenges:

In his final speech as president of the Royal Society, Lord May of Oxford will say scientists must speak out against the climate change “denial lobby”.

He will warn core scientific values are “under serious threat from resurgent fundamentalism, West and East”….

“There are serious problems that derive from the realities of the external world: climate change, loss of biological diversity, new and re-emerging diseases, and more.

“Many of these threats are not yet immediate, yet their non-linear character is such that we need to be acting today.

“And we have no evolutionary experience of acting on behalf of a distant future; we even lack basic understanding of important aspects of our own institutions and societies.

“Sadly, for many, the response is to retreat from complexity and difficulty by embracing the darkness of fundamentalist unreason.”