NASA’s James Hansen Reviews Draft American Meteorological Society Climate Statement: Stronger But Still Inadequate


Many television meteorologists question manmade climate change, including ones certified by the American Meteorological Society (AMS). The society’s statement on climate change is now more than five years old, overdue for a revision.

A few months ago, members of Forecast the Facts called on the AMS to pass a strong, science-based information statement on climate change. After months of delay, the AMS has finally completed a draft statement. The draft is only viewable by AMS members. Climate scientist Dr. James Hansen, director of NASA’s Goddard Institute for Space Studies, has read the statement and offers his opinion below.  — Brad Johnson, campaign manager of Forecast the Facts.

From James Hansen:

As a climate scientist, I know that there’s a huge gap between what scientists understand about climate change and what the public knows. And when TV meteorologists get the science wrong, it just furthers public confusion.

The American Meteorological Society has an important role to play in clearing up the confusion by giving clear guidance to their members. I’m pleased to say that their new climate change statement is largely in line with current science, but there is an important caveat, as I will explain. Here’s what I saw when I read the statement:

Overall, the statement is stronger than the AMS’ 2007 statement. The previous statement emphasized uncertainties and natural causes for climate change. By contrast, the new statement makes the unequivocal case for human-induced climate change.

The draft statement defends the merits of climate models as a tool for understanding climate change. This is important, because TV meteorologists often call these models unreliable in order to create doubt about climate science.

The draft statement acknowledges that severe weather events are expected to increase with global warming. The predictions include: More extreme precipitation events and more intense dry spells in between, more severe droughts, a higher proportion of strong hurricanes, and longer/more intense periods of extreme heat.

The current statement does not adequately describe major climate threats that concern scientists. Their statement does not make clear that we will guarantee enormous undesirable consequences for young people if we continue with rapid fossil fuel emissions to the atmosphere. For example, they note that sea level will rise 20 cm by 2100 due to thermal expansion of ocean water, but that underplays the fact that continued rapid warming will cause much larger sea level rise via ice sheet disintegration. The difficulty in predicting exact timing of sea level rise and location of increasing extreme climate anomalies does not diminish the threats that they pose.

My principal concern with the statement is that it assumes emissions will continue to grow. We must never accept “business-as-usual” as inevitable. If the U.S. and the international community joined together to put an honest price on carbon emissions, the exploitation of unconventional fossil fuels and coal could rapidly be phased out.

Overall, I’m pleased that the AMS is headed toward a strong, science-based statement, which will go a long way toward educating broadcast meteorologists who cover this important topic. I’ll be sending a note to the AMS thanking them for their progress so far, and encouraging them to continue improving upon this draft before the statement is finalized. Can you please join me by doing the same?

Click here to send a note to the AMS.

Factually yours,
Dr. James Hansen
Director, NASA Goddard Institute for Space Studies

P.S. If you’re interested in becoming a member of the AMS, you may do so here. Members are allowed to log in and read draft statements, including the the latest statement on climate change.

12 Responses to NASA’s James Hansen Reviews Draft American Meteorological Society Climate Statement: Stronger But Still Inadequate

  1. Raul M. says:

    Thanks good read.

  2. James wrote:

    “The difficulty in predicting exact timing of sea level rise and location of increasing extreme climate anomalies does not diminish the threats that they pose.”

    Actually, it makes the threats worse. Unpredictable, and perhaps non-linear rates of sea level change can make even short-term planning a nightmare.

  3. M Tucker says:

    “My principal concern with the statement is that it assumes emissions will continue to grow.”

    Well, they will for another decade or two. You can tell nothing is being done, and nothing will be done for a long time, because your defense of asserting that we should never assume uninterrupted emissions growth is prefaced by a big fat “if.” If the US and all other nations of the world adopted [insert policy statement here]. Well the US is not going to do anything meaningful for many years to come. The US and China will never commit to a strict policy unless they can defer the start date beyond 2030. India and several other developing nations are in the process of building new coal power plants now. China will continue to generate more than two-thirds of its electricity from coal for several decades. So given that the real uncertainty is: what will the policy be and when will it take effect, it seems reasonable to assume bau for at least the next 20 years.

    No my principle concern is that the AMS accurately represent the dangers and clearly specify who is likely to suffer the most from the ever increasing likelihood of extreme weather events.

  4. Raul M. says:

    Some are pointing to the fact of extreme weather events happening this year. Didn’t know that weather took time off from making extreme weather events.
    Seems the time is right to start thinking.

  5. Joan Savage says:

    I look forward to seeing if the AMS material includes operative links between meteorology and climate change.
    Let’s see if they provide their members with information, or at least an informed discussion about weather predictions that include the following topics that have come out within the past five years:

    a) Arctic ice melt’s role in the northern jet stream’s shift in location, strength, and frequency of blocking patterns.
    b) Temperature role in thickness of 500 mb atmospheric layer.
    c) Increase in atmospheric water vapor and consequences for development of regional downpours and droughts.
    d) Incidence of Gulf of Mexico warm temperature air undercutting cooler Rocky Mountain air, leading to supercell storms and likelihood of tornado swarms.

    Better weather prediction is of acute strategic importance; forecasters need an updated ‘toolkit.’

  6. colinc says:

    Better weather prediction is of acute strategic importance; forecasters need an updated ‘toolkit.’

    I’ve been visiting the Intellicast and Wunderground forecast pages several times a day, every day, for nearly the past decade for my area (a little W of CLE) and places I’ve lived in the past. Admittedly, I’ve yet to put those predictions to “paper” to analyze and document the changes that occur. Nonetheless, I can say with absolute certainty that weather forecasting has become much more challenging and seems to be heading toward utterly unpredictable and chaotic. I don’t think any ‘toolkit’ can be conceived to compensate for the weather “patterns” we’ve all grown up with trending toward a harmonic resonance.

    Yes, it seems the disappearing Arctic ice-cap is wreaking havoc with the jet-stream and associated weather patterns. How much more is it going to change as the summer ice is gone within 5 yrs and yr-round ice non-existent within 10-12? Personally, I’m looking at the last few years of global weather “anomalies” as akin to the first 5-10 minutes of a 4th of July fireworks display. The “beat” IS accelerating, intensifying and becoming much more ominous.

  7. Makan says:

    It’s a relief to see that the new AMS statement is largely in line with current science. And excellent to have this perspective from a well-known and credible scientist who knows the field so well.

    Many thanks…

  8. wili says:

    Meanwhile, the AIRS map for NH methane for March is out:

    Big increase in methane concentration over the East Siberian Arctic Shelf over last month:

    That really shouldn’t be happening up there at this time of year, since sunlight should be oxidizing/destroying methane now.

    Something would seem to be afoot.

  9. David Chamness says:

    So much talk about what James Hansen wants the US to do, because “business as usual” is so bad for the world. The CO2 emissions of the US are, at last count, only about 10% higher than they were in 1990. (source Our population has grown by 24%, meaning that our per capita CO2 emissions have gone down significantly.

    I would think declining per capita CO2 emissions would be a good thing. ALL of the increase in CO2 emissions per capita comes form somewhere else – mostly from the very countries that James Hansen wants us to send money to. When we send money to them, they use that money to build more power plants, more industry, more CO2.

    How about we start giving credit to the US for reducing our rates, and start pointing fingers overseas for a change?

  10. colinc says:

    Thanks, wili, those are truly sphincter-shrinking images.

  11. Joan Savage says:

    We can expect more dynamic perturbation as energy accumulates in the system. I don’t foresee a new plateau of what you call “harmonic resonance” until the energy level stabilizes, which is to say, many lifetimes away. None the less, weather forecasters need an honest toolkit that communicates both the likely events and the different kinds of uncertainties. If your local forecasters were working with out of date forecast models, that could have been limiting.

  12. Brad Johnson says:

    The problem is that accounting ignores the amount of pollution that’s generated by other countries on behalf of US consumption.