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More than 3/4s of Earth’s surface has become permanently drier, UN report says

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    More than 3/4s of Earth’s surface has become permanently drier, UN report says

    More than three-quarters of Earth’s surface has become permanently drier, UN report says

    Kate Helmore ([url]https://www.theglobeandmail.com/authors/kate-helmore/)Agriculture[/url] and food policy reporter
    Matthew McClearn ([url]https://www.theglobeandmail.com/authors/matthew-mcclearn/[/url])
    Published 5 hours ago

    An area of Earth larger than India has transformed from humid lands to dryland over the past three decades, destroying food systems, driving poverty and leading to water shortages across the globe, according to a new UN report.

    The report, prepared under the United Nations Convention to Combat Desertification’s Science-Policy Interface – the UN body for assessing the science of land degradation and drought – found that between 1990 and 2020, more than three-quarters of the Earth’s land became permanently drier. More than 40 per cent of the global land mass (excluding Antarctica) is now classified as drylands – up from 37 per cent in previous decades. Twice as many people worldwide live in drylands today compared with 1990.

    The report found that an area larger than Canada – equivalent to 7.6 per cent of all land – had been permanently transformed, for example from humid landscapes to drylands, or from forests into grasslands. China saw the largest total area permanently transformed; as a percentage of their total area, South Sudan and Tanzania were hit hardest.

    Ibrahim Thiaw, the convention’s executive secretary, called it “an existential threat affecting billions of people” in a written statement.

    Should high greenhouse-gas emissions continue, the authors forecast further expansion of drylands, including throughout the entire Mediterranean region, northern Venezuela, northeastern Brazil and large swaths of southern Africa. They would also grow on this continent, in central Mexico and across the American Midwest.

    Jonathan Overpeck, dean of the University of Michigan’s school of environment, said the report highlights the problem more comprehensively than previous efforts.

    But he said that while the report is “sophisticated and impressive,” it understates the problem’s extent. That’s because it focuses on moisture available through precipitation, but overlooks water locked up in ice. In many regions, snow and ice allow “moisture in the warmer months, because instead of raining in the winter, you get the snow, which persists on the land longer. … It’s sort of like a natural reservoir.” But climate change is melting that ice in mountainous regions including the Himalayas, the Andes and the Alps.

    Prof. Overpeck added that the report also didn’t take into account the role of melting permafrost, which causes soil and vegetation to dry out.

    “That’s really devastating for forests in Northern Canada and other parts of the boreal forest around the globe,” he said.

    Though aridity and drought are often conflated, they are in fact distinct: The main difference is that while droughts can persist for months or years, they eventually end, allowing people and ecosystems to recover. But rising aridity is a permanent change that can’t be waited out; the only option is to adapt.

    “There’s no going back from aridity,” said Narcisa Pricope, one of the report’s authors.

    Greenhouse-gas emissions lead to increased aridity through trapping more heat in the atmosphere. These increased temperatures exacerbate water evaporation, therefore removing moisture from soil.

    Aridity is a vicious cycle. As the soil becomes drier it is less able to sustain ecosystems, which means fewer plants grow, so less dead plant matter is absorbed by the soil. Dead plants within soil – detritus vegetation – trap moisture, which in turn feeds the soil and the ecosystem.

    However, agricultural practices can also contribute to dryness – notably the use of fertilizer, which robs the soil of moisture-rich biodiversity, or by tillage, whereby soil is fractured, leading to increased runoff, erosion and a surface crust that water cannot infiltrate.

    When more than half the world’s agricultural land and its soils are degrading, UNCCD chief scientist Barron Orr said, “your risk goes up, you have less cover and you are exacerbating the aridity trend.”

    However, while increased aridity is a worldwide crisis, it presents an opportunity for Canadian agriculture, said Evan Fraser, director of the Arrell Food Institute at the University of Guelph.

    Canadian producers still have access to huge areas of arable land and water, alongside infrastructure and energy, such as solar and hydro, he said. Compared with other agricultural countries, production in Canada is also efficient and well regulated, with sustainable practices that have the capacity to carry into a drier and more arid future.

    The Canadian resilience to dry conditions can be seen in arid landscapes within the Prairies, said Margot Hurlbert, a researcher at the University of Regina. Despite a four-year drought, farmers have nevertheless managed to maintain yields through practices such as crop rotation, minimizing tillage and allowing soil to recover during some growing seasons. Planting less water-intense crops are also a key part of the solution, she said.

    However, simply because these measures have worked during past droughts does not mean they will continue to work, Prof. Hurlbert said.

    “We know droughts will get more intense over the next few years. The key is balance and recovery and diversifying the risk.”

    To Mr. Orr, sustainable, water-focused agricultural policies in Canada and elsewhere are key to fighting increased aridity on a global scale. By subsidizing and promoting practices that lead to healthy soil – which in turn sequesters carbon – overall worldwide emissions can be reduced.

    “Aridity is resulting from cascading effects that stem from climate change,” he said. “But we could try and have a positive, enhancing feedback loop too, maybe not as rapid but nonetheless long-term.”

    #2
    An important scientific study?

    Comment


      #3
      Originally posted by shtferbrains View Post
      An important scientific study?
      I'm much more impressed with the fact that based on 30 years of data this scientific study can establish that a trend is permanent. Permanent is a long time compared to 30 years.

      Isn't science wonderful.

      Comment


        #4
        I wish he could find "articles" that discussed an oil replacement. That's going to imperil humans long before and far faster than the climate.
        Of course that would also involve a taboo word like profit, so waiting on something biblical I guess.
        Last edited by blackpowder; Dec 9, 2024, 11:15.

        Comment


          #5
          .....

          Comment


            #6
            Define what the author means by "permanently drier". One would have to believe the author means a period of three decades is permanent. Is that your definition of permanent?

            Mine would be that that is a long time if arrived at gradually, but the prairies have had 50 year drought periods. Or it could be like northern Africa flooding in 2024, and it greened up in no time.

            Sorry, AF5, just read your post while scrolling back to article.

            Comment


              #7
              OMG - Really?

              Comment


                #8
                Lol.
                i mean.
                Alright. Well.
                Fine.

                BUT if the oceans are rising and oceans cause rain.... then what pct of land ( coastal) will see heavier rains which will cause rains deeper inland.


                Take kelowna and vernon area for instance. If the ocean rose and flooded out Chilliwack .. would that extra water cause rain in the vernon area? Osoyoos more of a temperate rainforest rather than the super dry desert area it is now?

                its not like global warming is going to flood out the coasts overnight. If scientists know its coming then are there not VAST areas that will become both permanently wetter and warmer and able to grow different crops?

                Heres a thought.
                If the war if russia hadnt happened and ALL of the money that was spend on armor/ weapons/ infrastructure etc was spent on moving people inland from.the coasts...

                How much could be done?




                If you arent gonna stop global warming, then just move every one 50 feet. Boom. Done

                i say that in jest but... alot of these models cant predict what the weather will be like in the future in areas that will become affected by sea rise.
                maybe the sahara becomes the new mecca of high yielding wheat?


                Comment


                  #9
                  Originally posted by goalieguy847 View Post

                  BUT if the oceans are rising and oceans cause rain.... then what pct of land ( coastal) will see heavier rains which will cause rains deeper inland.

                  Already happening.
                  Since 1901, global precipitation has increased by an average of 0.03 inches per decade. The frequency of heavy precipitation has also increased, with a 13% increase from 1998 to 2019

                  What's even more amazing is that droughts are also decreasing over the same time period. And I apologize for the screenshot from facebook. My phone won't let me put a proper link for some reason.

                  Comment


                    #10
                    UN WEF NATO all run by lunatics, probably put WHO and a few others in the propaganda machine list….

                    Comment


                      #11
                      Hohum yawn. Man oh man went hard here in oz our biggest river system will NEVER flood again become a series of pot holes filled with water hmmm not sure maybe 2005 the big statement most took it for humour had third biggest flood since white man in 22 and gonna rise again till minor in 25.

                      The rhetoric is borderline ignored now. We all know the alternate opinions truth lies in the middle.

                      Let Chuck cut and paste its fine don’t have to agree don’t have to respond.

                      He needs Agriville.

                      Comment


                        #12
                        So science and evidence doesn't matter?

                        Where are the references for Lomborg's claims on social media? One unreferenced post on social media isn't much to base your opinions on!

                        Is there wide agreement among many sources that droughts are decreasing?
                        I doubt it.

                        Show us a comprehensive study that proves the authors are wrong about aridity increasing in a warming world.

                        Otherwise its just more hot air from climate change deniers who don't even think that the glaciers are melting or that the arctic and antarctic are losing ice mass.

                        Its the antiscience crowd who only support science that agrees with their climate change denial.

                        Agrisilly the site that is home to flat earthers and climate change deniers!




                        Last edited by chuckChuck; Dec 10, 2024, 08:08.

                        Comment


                          #13
                          Mile of ice over my head if the glaciers didn’t melt, give up chuckroach your propaganda don’t mean s*it.

                          Comment


                            #14
                            Its science from thousands of diverse sources and scientists.

                            So which credible scientists and their organizations are saying climate change is not happening nor a threat to the planet?

                            All we get is crickets every time! Chirp Chirp!




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