Science and Technology links (April 6th 2019)

  1. In a randomized trial where people reduced their caloric intake by 15% for two years, it was found that reducing calories slowed aging. This is well documented in animals, going all the way to worms and insects, but we now have some evidence that it applies to human being as well. Personnally I do not engage in either caloric restriction or fasting, but I am convinced it would be good for me to do so.
  2. What is the likely economic impact of climate change over the coming century? We do not know for sure. However, all estimates point to a modest impact, always significantly less than 10% of the size of the economy over a century while the world’s economy grows at about 3% a year.

    Clearly, 27 estimates are a thin basis for drawing definitive conclusions about the total welfare impacts of climate change. (…) it is unclear whether climate change will lead to a net welfare gain or loss. At the same time, however, despite the variety of methods used to estimate welfare impacts, researchers agree on the order of magnitude, with the welfare change caused by climate change being equivalent to the welfare change caused by an income change of a few percent. That is, these estimates suggest that a century of climate change is about as good/bad for welfare as a year of economic growth.

  3. Is the scientific establishment biased against women or not? Miller reports on new research showing that men tend to reject evidence of bias whereas women tend to reject contrary evidence.
  4. Technology greatly improved the productivity of farming. We are often told that the reason we did not see famines on a massive scale despite earlier predictions to that effect (e.g., by the Club of Rome) is due to the so-called Green Revolution. It is seems that this not well founded on facts:

    We argue a political myth of the Green Revolution focused on averted famine is not well grounded in evidence and thus has potential to mislead to the extent it guides thinking and action related to technological innovation. We recommend an alternative narrative: The Green Evolution, in which sustainable improvements in agricultural productivity did not necessarily avert a global famine, but nonetheless profoundly shaped the modern world.

  5. Sugar does not give your mood a boost. We do not feel more energetic after eating sugar.
  6. Though e-cigarettes are probably incomparably safer than actual cigarettes, people have been banning them on the ground that e-cigarettes might be a gateway toward cigarettes. They are likely wrong. If anything, e-cigarettes are probably a solution for people who have not managed to stop smoking by other means. They have been found to be a highly effective way to stop smoking. Thus e-cigarettes are likely saving lifes; people who ban e-cigarettes despite the evidence should have to answer for the consequences of their choices.
  7. People who think that little boys are more physically aggressive than little girls because of how they are raised are likely wrong.
  8. I am impressed with the courage of these researchers: Oral sex is associated with reduced incidence of recurrent miscarriage (Journal of Reproductive Immunology, 2019).

Published by

Daniel Lemire

A computer science professor at the University of Quebec (TELUQ).

12 thoughts on “Science and Technology links (April 6th 2019)”

  1. Re 2: GDP by itself is a completely inadequate measure, as the world’s population is still growing.

    How about this estimate instead:
    (51% chance of a GDP per capita decline above 20%). Doesn’t seem modest at all.

    And of course there’s this little issue of how the impact is distributed. The model above predicts declines of 80-100% in GDP per capita for many countries by 2100 (aka utter devastation).

    Additionally, Nordhaus, for one, has been completely delusional about the real-world impacts of climate change, so I seriously doubt the accuracy of his models. And what about the other economists, when most of them are wedded to the idea of perpetual economic growth?

    1. Thanks. Let me quote from the link I provided:

      With the exception of Burke, Hsiang, and Miguel (2015), these studies find relatively small effects.

      So, yes, Burke, Hsiang, and Miguel (2015) is an outlier that I did not mention in my summary.

  2. I would take issue with #2 (impact of climate change on the economy). In the next century, if we are 3 deg C warmer on average, there are surely going to be significant impacts. Yes, Canada may be fine, but certainly the US will not be. Increasing drought throughout the west for sure. A lot of risk to food production in the bread basket.

    And the impacts do not end after one century. Even if emissions cease (unlikely), temps will continue rising. Do not make light of this issue.

    1. Quoting from the link I provided:

      It is very difficult to make sense of the many and different effects: crops hit by worsening drought, crops growing faster because of carbon dioxide fertilization, heat stress increasing, cold stress decreasing, sea levels rising, increasing energy demand for cooling, decreasing energy demand for heating, infectious disease spreading, species going extinct. Thus we need aggregate indicators to assess whether climate change is, on balance, a good thing or a bad thing and whether the climate problem is small or large relative to the many other problems that society faces.

      1. Crops do indeed grow faster. However, I recall a study from a while back which I believe you cited that stated that the mass of nutrients remained the same although the mass of crop increased.

        1. I have to believe that the content of the food we get today is quite a bit different from the content of the food we got in the past. Climate and CO2 have and will continue to play a role in these changes.

          However, I doubt that it is anything like “the mass of nutrients remained the same although the mass of crop increased”. That sounds a bit too much like bad science fiction.

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