Scientists Are Making Stronger Links Between Climate Change and Extreme Weather

Mar 15, 2016

Photo credit: Kristian Bell—Getty Images/RooM RF

By Justin Worland

Every time an extreme weather event strikes—from Hurricane Katrina to the California drought—observers wonder what role climate change may have played. And for years any reputable scientist, politician or journalist would respond that while global warming might play a role, no specific weather event could be attributed to climate change.

That is changing. New research from the National Academy of Sciences suggests that’s no longer the case: scientists can now determine with some confidence the degree climate change influenced some extreme weather events.

“The days of saying no single weather event can be linked to climate change are over,” says Heidi Cullen, chief scientist at Climate Central, a nonprofit news organization that reports on global warming. “This report makes a really important contribution in linking global warming to extreme weather.”

The report follows a decade of research by a variety of scientists in different fields dedicated to attributing weather to climate change. The new field has evolved rapidly, though it still can’t provide quick and definitive answers for every weather event. Scientists are best equipped to show the connection between extreme weather events and climate change when the effects are closely related to temperature. Extreme heat and extreme cold are the easiest to attribute to climate change, followed by drought and extreme rainfall. The effect of climate change on weather events like tornadoes and wildfires can be especially difficult to assess because of the many variables that come into play, including factors beyond weather, like settlement patterns.

The National Academy report lays out a system of best practices that incorporates the historical record—looking back—and model simulations—looking forward—to increase confidence when assessing the link between climate change and an individual weather event. The historical record approach looks at how much an event deviates from past weather while simulation approaches often assess expected weather in the absence of climate change.

The authors of the report emphasized that researchers have to ask the right questions to get the right answer. It’s not a question of whether climate change directly caused a specific event, given the many various factors that play into weather. Instead, scientists should study to what extent warming contributed to extreme weather, in part by trying to figure out how likely the event would have been to occur in the absence of climate change.


Source: http://time.com/4255428/climate-change-extreme-weather/

26 comments on “Scientists Are Making Stronger Links Between Climate Change and Extreme Weather

  • I’m not suggesting this could not be true, but just remember that correlation doesn’t necessarily means causation. I just think that if true, there should be a better way to explain it. Perhaps there is, and they just haven’t found it yet.



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  • Probabilities of causal relationships can be established by epidemiologosts, so why not here? We need these probabilities to galvanise action.

    Any container of fluid becomes more energetic in its movements when heated. The model, at base, is this simple



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  • phil rimmer #3
    Mar 19, 2016 at 8:18 am

    Any container of fluid becomes more energetic in its movements when heated. The model, at base, is this simple.

    I don’t think anyone is going to find a better way to explain that!!



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  • Confirmation bias much ?
    Galvanize action by demagoguing adhoc ergo potor hoc ‘reasoning?
    Research perhaps , science ? not so much
    The simple example of the heated fluid filled vessel , does nothing to iilistrate from whence the
    heat came.
    It reads more like neoscientists helping politicians to a power grab.



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  • thad #5
    Mar 20, 2016 at 1:44 pm

    The simple example of the heated fluid filled vessel , does nothing to iilustrate from whence the heat came.

    Oh dear! We really seem to need to go back to school-level basics of physics here!

    The heat comes mainly from the Sun, and the heat loss is reduced by the greenhouse effect of CO2 catalysing increased water vapour, leading to greater planetary heat retention.

    Hotter atmospheres and oceans, lead to more forceful weather systems, which are powered by the overall energy levels and the contrasts within the mixtures.



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  • @thadd #5

    The model illustrates why, given global warming there is more extreme weather. Your task, should you wish to dispute this, is argue why more extreme weather may come about without global warming.

    Begin.



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  • I don’t know if I would dispute that a change in climate would not involve a resultant
    change in weather.
    I am a layman, though climate change certainly seems as if it involves changes to weather ,
    even some that could be described as extreme . If I’m not mistaken the Great Lakes of North
    America were created during a glacial period and its interaction with the local topography and
    geology.



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  • @thadd

    This is the key error you are making.

    In physics, the law of conservation of energy states energy can neither be created nor destroyed; rather, it transforms from one form to another. For instance, chemical energy can be converted to kinetic energy in the explosion of a stick of dynamite.

    The extra energy being trapped by global warming doesn’t just sit and do nothing. The extra energy in the earth’s weather system gets converted and converted… Whatever the weather was doing previously at lower energy levels, it is still doing, only with more energy. That is, the winds are stronger. The Highs, higher. The Lows, lower. Rains heavier. Droughts drier, longer. More record high and low temperatures. All are a consequence of the extra energy trapped by CO2 as a result of the green house effect magnifying the normal weather.

    If you put a higher octane gasoline in your car, it has more power. That is the conservation of energy principle.

    You may hear global warming deniers going apoplectic over the increased sea ice around Antarctica. “See”. They scream. “More ice. No such thing as global warming.” But the extra sea ice is actually a result of the extra energy trapped on earth by global warming. In dot point. The extra energy increases the strength of the southern hemisphere polar vortex, a wind that blows around the bottom of the earth, unimpeded by any continents. Know as the Roaring 60s.

    This stronger wind pulls at the edge of the sea ice around Antarctica, pulling chunks away. It has always done this, but now the extra energy can move larger chunks further away from Antarctica. As the chunks move away, the open sea left behind freezes over. The chunks bump back and forth all winter repeating the process, but the net result is that Antarctica’s sea ice is expanding, but it entirely due to global warming.

    Here is a link to Australia’s premier science channel who did a special on this very subject and got the actual research scientists to explain their findings. I commend it, and the Law of Conservation of Energy to your intellect.

    http://www.abc.net.au/catalyst/stories/4056545.htm



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  • thad #8
    Mar 20, 2016 at 10:46 pm

    I don’t know if I would dispute that a change in climate would not involve a resultant change in weather.

    “Climate” is “weather” looked at over a long time scale.

    The question is not: “Is the weather changing in the short-term because the atmospheric heating is changing in the long term?”

    The question presented is: “Are particular local weather events attributable to the long-term changes?”

    It is beyond doubt, that the planet is heating up, and that this heat will increase the severity and mobility of weather events, such as droughts, floods, hurricanes, polar or tropical air travelling further across the globe than previously.

    I am a layman, though climate change certainly seems as if it involves changes to weather , even some that could be described as extreme .

    Climate records are compiled by recording weather (temperature, rainfall, snow, hours of sunshine etc.) world-wide and building up an overall picture spanning year,s centuries, millennia, an even further back in time.

    If I’m not mistaken the Great Lakes of North America were created during a glacial period and its interaction with the local topography and
    geology.

    There have in fact been many periods of glaciation on Earth. They come around in regular cycles. Climate scientists, geologists, astronomers and glaciologists, have plotted them going back thousand or millions of years and matching level of sunlight, CO2 and CH4 to the temperature changes. Here is an article with some graphs which explain it.

    https://en.wikipedia.org/wiki/Milankovitch_cycles#Effect_exceeds_cause



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  • David R Allen #9
    Mar 21, 2016 at 2:29 am

    If you put a higher octane gasoline in your car, it has more power. That is the conservation of energy principle.

    Please sir (waves hand frantically). Race engine designer here. Fuel octane does not correlate with power albeit this being a common misconception. In fact octane value only quantifies the fuel’s resistance to detonation and bears no relation to the calorific value of the fuel which in fact is often lower as octane value rises due to the extra additives involved which suppress detonation but also don’t release much energy.

    What higher octane fuel does do is allow higher compression ratios without detonation which then in turn may allow the engine to produce more power but using a higher octane fuel than a particular engine actually requires to operate without detonation brings no benefit whatsoever.

    Unfortunately phrases in common parlance like “high octane thrills and spills” has led to a false equivalency between octane value and power in the general perception.



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  • The overwhelming scientific consensus is that global warming is real and is directly related to increasing CO2 emissions – hence the global need to reduce the latter. What puzzles me is why there hasn’t been a coordinated effort to massively plant rapidly growing trees and other types of greenery across the world to remove the offending gas?



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  • Erol #12
    Mar 21, 2016 at 7:29 am

    What puzzles me is why there hasn’t been a coordinated effort to massively plant rapidly growing trees and other types of greenery across the world to remove the offending gas?

    The short answer is “money”!
    It is primarily tropical forests which remove CO2, (Although ocean phytoplankton also do an excellent job).

    Unfortunately logging and illegal logging, along with burning of bio-fuels, quickly returns this CO2 to the atmosphere.

    Most planting is simply struggling to replace what is being lost.



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  • Alan – If the world’s governments are aware of the problem of rising CO2 levels and the danger it poses for civilisation as we know it, how can money spent on planting trees be an issue? It must surely be one of the cheapest options available to combat the dilemma of rising CO2 levels! You’re probably correct – but I would find it astonishing if money’s indeed the main problem here.



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  • Erol #14
    Mar 21, 2016 at 7:55 am

    Alan – If the world’s governments are aware of the problem of rising CO2 levels and the danger it poses for civilisation as we know it, how can money spent on planting trees be an issue?

    The cost of tree production and planting is not the issue. After the land is prepared for a temperate conifer plantation, a single forester can plant a thousand cheaply produced 2 to 3 year old, trees in a day. – But the time scale for harvesting timber is a minimum of a 40 year cycle.
    Quicker profits can be achieved by asset stripping established forests, and other forms of land use. (Such as Amazon cattle-ranching, or pacific island oil-palm plantations).



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  • Alan – if ‘quicker profits’ are going to be a main driving force then governments should be willing to offer it to those able to do the tree planting. The global warming risks are too high to allow the profit motive to hinder what could be the simplest way of solving the rising CO2 level dilemma. Political will is evidently required to get this started.



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  • @erol #16

    The problem to solve is that of an economy addicted and facilitated to short term investments, which too often serve as zero-sum gambling. Further, since the mathematics of investment showed in the eighties, such systems can be advantageously gamed, provided the sums gambled (sorry invested) are the largest to be played.

    To get to an economic environment that facilitates rational plans like yours you must persuade the politicians forming governments to abandon the financial interests that have either bought them or are keeping a seat warm for them in favour of a more sober style of institution that appreciates stability and long term investment. These two latter are mutually dependent and self sustaining, indeed are the essential ingredient to all sustainability strategies, but hard to get to without governments providing clear tax advantages to long and very long investment…One day…

    I am at a loss, however, how to deal with the troublesome psycho-parasites who game values a hundred times the actual global GDP per year, who should by rights be retired with prejudice. Maybe unlimited cocaine?



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  • @Phil #17

    I’ve seen evidence in news broadcasts of the real concern many of the world’s governments have regarding global warming and that ‘something’ seriously needs to be done about it. Most of the discussion currently focuses on cutting emissions for ‘rich’ nations while delaying the same for those third world countries that are still in the ‘development’ stage. This is hardly going to achieve much in the near term. And yet nobody seems to want to implement or even discuss methods of reducing atmospheric CO2, of which tree plantation would appear to be very feasible – if only it could be made profitable!



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  • @Olgun #18

    No, I hadn’t seen that – I need to remember that there’s likely to be a Wikipedia entry for just about any subject one could care to discuss about!

    Having said that the article does state the following: “The development of markets for tradeable pollution permits in recent years have opened up a new source of funding for tree planting projects: carbon offsets. The creation of carbon offsets from tree planting projects hinges on the notion that trees help to mitigate climate change by sequestering carbon dioxide as they grow. However, the science linking trees and climate change is largely unsettled, and trees remain a controversial source of offsets.”

    And then later it states: “As little as US$90 will plant 900 trees, enough to annually remove as much carbon dioxide as is annually generated by the fossil-fuel usage of an average United States resident.”

    Much food for thought!



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  • @erol #19

    The problem with just tree planting, e.g. in the vast open spaces of higher latitudes is the effective reduction of albedo to the planet surface. Evergreens gobble up light unlike the whitened grass of a frosty tundra. This would accelerated the effective warming from insolation.

    The problem is not quite so simple.

    Transgenic trees were developed that had very high rates of growth (carbon fixing) but the risks were deemed insanely high given the disruption possible to eco-systems.

    My own favoured solution is the the use of some of the light leaved version of the ginkgo biloba (female cultivar), at least in temperate regions. My sister had one in her garden. Utterly beautiful. Elegant by being one of the earliest, least evolved trees on the planet. 270 million years old. Carbon fixing, albedo lifting and tough as old boots…



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  • @ Erol 20

    People here know a hell of a lot more about it than I do and when I read that more trees can actually raise global warming even though they trap CO2 leaves me not knowing where to go next with it?

    I used to have a 50ft conifer in my small garden that I used to sit under in the heat of summer. It took me a while to understand why I liked sitting under it even though the sap would irritate my eyes a bit. I found out one day that the updraft caused by this tree (and whatever else?) opened up my dodgy lungs and gave me a positive buzz. I liken it to being in an oxygen tent (not that I have ever been in one). We had to get rid of it in the end because we had no garden left. It was one of those leylandii things!1



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  • Erol #16
    Mar 21, 2016 at 9:27 am

    Alan – if ‘quicker profits’ are going to be a main driving force then governments should be willing to offer it to those able to do the tree planting. The global warming risks are too high to allow the profit motive to hinder what could be the simplest way of solving the rising CO2 level dilemma.

    Tree planting which is useful , is not the simplest way to manage CO2 pollution.

    There are many other options which were covered in earlier discussions.

    https://www.richarddawkins.net/2015/12/what-just-happened-in-solar-is-a-bigger-deal-than-oil-exports/#li-comment-193135

    https://www.richarddawkins.net/2014/06/germany-can-now-produce-half-its-energy-from-solar/#li-comment-146303

    https://www.richarddawkins.net/2014/06/germany-can-now-produce-half-its-energy-from-solar/#li-comment-146308

    https://www.richarddawkins.net/2014/06/germany-can-now-produce-half-its-energy-from-solar/#li-comment-146309



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  • Erol #20
    Mar 21, 2016 at 10:57 am

    And then later it states: “As little as US$90 will plant 900 trees, enough to annually remove as much carbon dioxide as is annually generated by the fossil-fuel usage of an average United States resident.”

    I think they are playing with slippery statistics here!

    It will be many years before a newly planted tree fixes any significant amount of carbon at all!!



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  • If this work is going to continue to provide hard data, they need to keep the tools in place, working, and up to date!

    http://www.bbc.co.uk/news/science-environment-35886817

    European scientists are worried they could soon lose a vital tool for monitoring Earth’s ice fields.

    The Cryosat-2 radar spacecraft has transformed studies of the Arctic, the Antarctic and Greenland, but is now operating beyond its design lifetime.

    A group of 179 researchers is concerned the ageing mission could die in orbit at any time.

    They have urged the European Commission (EC) and the European Space Agency (Esa) to start planning a replacement.

    “The mission is now central to international efforts to monitor the state of the cryosphere,” they write in a letter to top officials at the EC and Esa.

    Cryosat-2 was launched in 2010 on what was initially supposed to be just a one-off, three-and-half-year observation of marine and land ice – to get a snapshot of any gains and losses.

    But the performance of the spacecraft’s mapping instrument – its SAR/Interferometric Radar Altimeter (Siral) – has exceeded all expectations, and made for some compelling data-sets.

    The satellite has delivered the first complete assessment of Arctic sea-ice thickness and volume, as well as the most precise measurements yet of the volume and mass of the great ice sheets covering Antarctica and Greenland.

    It is a capability the scientists are loath to give up.

    How long Cryosat-2 can keep working is anyone’s guess. It has enough fuel to sustain itself into the early 2020s but component failure in the harsh environment of its orbit, 720km above the Earth, is an ever-present risk.



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  • Meanwhile some good progress is being made on the technology front, but more needs to be done!

    http://www.bbc.co.uk/news/science-environment-35891876

    Global investment in renewable energy hit a record US$285.9bn (£202.3bn) in 2015, beating the previous high of $278.5bn set in 2011, a study shows.

    The 10th Global Trends in Renewable Energy Investment also showed that investment in developing nations exceeded that in developed countries.

    In another first, more new renewables capacity than fossil-fuel generation came online during 2015.

    But it warned that much more had to be done to avoid dangerous climate change.

    The assessment, produced by the Frankfurt School-Unep Collaborating Centre for Climate and Sustainable Energy Finance and Bloomberg New Energy Finance, showed that the developing world committed a total of US$156bn (up 19% on 2014 levels) in renewables (excluding large hydro) while developed nations invested US$130bn (down 8% from 2014 levels).

    A large element in this turnaround was China, which lifted its investment by 17% to US$102.9bn, or 36% of the world total,” the report observed.

    However, other developing nations also contributed as six of the top 10 investors were developing nations.

    In the foreword, UN secretary-general Ban Ki-moon said the report’s findings increased confidence that a low-carbon world was obtainable.

    He wrote: “We have entered a new era of clean energy growth that can fuel a future of opportunity and greater prosperity for every person on the planet.”

    However, he warned that in order to avoid dangerous climate change required an “immediate shift away from fossil fuels”.

    Prof Moslener added that renewable generation was still dwarfed by fossil fuel-based sources, and only accounted for 10% of the global mix.

    “That shows us that we are quite far from having a system that is based on renewables,” he told BBC News.

    Lead author Angus McCrone, chief editor at Bloomberg New Energy Finance, said that although global oil prices had fallen sharply recently, the cost of generating electricity via renewables had also decreased significantly, adding that there were also other factors that made the industry attractive to investors.

    “One advantage that renewables has is that it can be built very quickly,” he explained.

    “If you are a power-hungry emerging market in Africa or South America, for instance, you can put up a wind farm in six to nine months, or a solar plant in three to six months.

    “However, if you want to put up a coal-fired power station, it is going to take three or four years. A nuclear power plant is going to take substantially longer than that.”



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