Month: January 2021

From Yahoo News via the Christian Science Monitor

A new team is trying a new approach to climate modeling using AI and machine learning. Time will tell if there is a positive effort or an extremely complicated exercise in curve fitting. Your goal is to create regional-level predictive models that are useful for planning. Few publicly admit that despite thousands of “studies” with scaled-down GCMs, these do not exist today.

“There are some things that have very robust results and other things that those results are not that robust,” says Gavin Schmidt, director of NASA’s prestigious climate modeling program at the Goddard Institute for Space Studies. But the deviations urge skeptics to dismiss the whole field.

“There are enough things out there that people can choose to support their prejudices,” says Dr. Housefather. “Climate skeptics … argued that climate models always predict too much warming.” After studying the models of the past 50 years, Dr. Hausfather: “It turns out they did remarkably well.”

However, climate modellers recognize that accuracy needs to be improved in order to find a way through the climate crisis. Now, a team of climatologists, oceanographers and computer scientists on the east and west coasts of the United States have started a brave race to do just that.

They have brought together some of the best experts from around the world to start building a new, modern climate model. They hope to correct the enormous flow of data from sensors in space, on land and in the ocean and use “machine learning”, a type of artificial intelligence, to bring their model to life and provide new insights into what many believe is it most pressing threat to the planet.

Their goal is to provide accurate climate predictions that can tell local policymakers, builders and planners what changes can be expected by when, with the numerical probability that weather forecasts now describe a rain probability of 70%, for example.

Tapio Schneider, a Germany-born climatologist at the California Institute of Technology and Jet Propulsion Laboratory in Pasadena, California, is leading the effort.

“We don’t have good information for planning,” said Dr. Tailors a gathering of scientists in 2019. Models can’t tell New York City how tall it is to build walls, or California how much it will spend protecting its vast water infrastructure.

They just vary too much. For example, in Paris in 2015, 196 countries agreed that it will have alarming consequences if the planet, measured against the industrial age, warms up by 2 degrees Celsius. But when do we get there? From 29 leading climate models the answer ranges from 20 to 40 more years – almost the difference of a human generation – below the current emission values. This area is too large to schedule actions that require extensive new infrastructure, from replacing fossil fuels to moving to electric vehicles to lifting houses.

“It is important to make better predictions and make them quickly,” says Dr. Cutter.

This is funny

And it threatens to ripple feathers in the world of climate science, especially in established modeling centers like Dr. Schmidt in Goddard. “I think they oversold what they can do,” says Dr. Schmidt. Do you need a new model? “You would say yes. I would probably say no. “

Apparently a fairly modest group.

The other differentiator, notes Dr. Marshall, are the ones who are working on it. “The model is actually less important than the team of scientists you have around you,” he says. In fact, the 60 to 70 researchers and programmers in the CliMA group represent a true United Nations.

Somebody hung a map on the wall of the CliMA house, a converted provost house in Caltech, and asked everyone to identify their houses. “There were a lot of needles,” says Dr. Cutter.

Here’s the AI ​​part

A climate model that “learns”

CliMA decided to take an innovative approach to use machine learning. Satellite and sensor information is freely available – much of it for weather forecasts. Dr. Schneider intends to “train” his model on data from the past three decades and then routinely provide it with the latest updates. The model itself could “learn” from the data and calibrate its performance using formulas refined by AI, even if the climate changes.

Other topics discussed include the reasons for choosing to program in Julia. To read the rest of the way, check out the full article here.

HT / Clyde Spencer

Like this:

To like Loading…

connected

Axions are a hypothetical particle that could explain the existence of dark matter. But it can occasionally interact with normal matter, especially in the cores of stars. A team of physicists looked for evidence of axions in Betelgeuse and found nothing. It doesn’t mean the axion doesn’t exist, but it does mean it will be harder to find.

We don’t know what dark matter is. This is the name we give to the component of the universe that makes up 85% of the total mass. Whatever it is, it is a form of particle unknown to the Standard Model of Physics. It is also hardly allowed to interact with photons or normal matter, otherwise we would have seen it by now. There are many candidates for dark matter, and a family of candidate particles are known as axions, which are predicted in various theories of high energy physics.

At first glance, the Axion fits the bill, as it is small and light and almost never interacts with light or normal matter. Nearly. If the axion is of a certain type known as an “microlight” it may be detectable through a process known as the Primakoff effect. This effect needs a few ingredients to work. Occasionally, when a photon is embedded in a super strong magnetic field, it can decide to turn into an axion. This axion would then move where it wants, since it doesn’t really interact with anything else. When this axion hits another magnetic field, however, it can turn back into a photon, usually something high-energy like an X-ray that gives off a flash of light that betrays the existence of the axion and the Primakoff effect.

Stars have really strong magnetic fields in their cores, so they could be axion factories. And these axions can give off X-rays. We’d love to use our sun as a laboratory for this, but unfortunately it’s busy releasing all kinds of X-rays for reasons of its own, and so it’s hard to tell whether they’re coming from axions or something far less exotic.

https://www.youtube.com/watch?v=uZXlQuXuwA8

But Betelgeuse is a different story. It’s a huge star towards the end of its life. It’s much cooler than the sun, so it hardly emits any X-rays. So if axions exist and the Primakoff effect is correct, Betelgeuse should be emitting a detectable amount of x-rays.

An MIT-based team of researchers did just that … and found squats. No x-ray. No signs of axions.

“Our results say that if you want to look for those really light particles that we were looking for, they don’t talk to photons a lot,” says Kerstin Perez, assistant professor of physics at MIT. “We basically make everyone’s life harder because we say, ‘You’re going to have to think of something else that would give you an axion signal.'”

These results do not completely exclude the existence of axions. It just means that if they are ultralight, their ability to convert to photons and vice versa must be very low. In fact, using Betelgeuse alone, these results place limitations on this ease of transition that are three times greater than any laboratory experiment.

So we’ll keep hunting.

Like this:

To like Loading…

Guest essay by Eric Worrall

Malthus, Ehrlich and The Club of Rome may have got it all wrong, but Waikato Professor Michael Cameron believes that we need to think about their work and limit population growth to prevent a future food crisis from anthropogenic CO2 emissions.

Containing Population Growth to Combat Climate Change: It’s a Tough Question

January 25, 2021, 5:50 a.m. AEDT

Michael P. Cameron
Associate Professor of Economics, Waikato University

Population growth plays a role in environmental damage and climate change.

…

The English political economist Thomas Robert Malthus put forward a compelling argument against overpopulation in his famous 1798 book An Essay on the Principle of Population

…

But his essay could not have been worse as it neared the beginning of the longest period of sustained global population growth in history. This was due in part to huge improvements in agricultural productivity over time.

This idea of ​​hard environmental limits for population growth was promoted in 20th century publications such as The Population Bomb, a 1968 book by Stanford biologist Paul Ehrlich, and The Limits to Growth, a publication by the Club of Rome think tank from the Year 1972, revived.

The implications of these papers on the threats of population growth suggest that population control is an important measure in limiting carbon dioxide (CO₂) emissions and global climate change.

…

That leaves population control, but the problems here are no less challenging. Government-led population control poses serious moral questions to democratic countries.

For this reason, China is the only country that implemented a (moderately) successful form of population control through the one-child policy from 1979 to 2015. During this period, the total fertility rate in China has roughly halved.

…

Read more: https://theconversation.com/curb-population-growth-to-tackle-climate-change-now-thats-a-tough-ask-153382

To be fair, the professor goes on to say that wealth may be enough to limit population growth, though I personally find it repulsive to call China’s disastrous and cruel one-child policies any sort of success.

Is There a Hard Limit on Population Growth? There has to be a limit, it is impossible that the earth can support an infinite number of people. But 200 years of failed series demise suggests that those who fear we are approaching a hard line for the world’s population are almost certainly wrong.

4.7
7th
be right

Item rating

Like this:

To like Loading…

connected