<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">“Decarbonization of the world’s economy would bring <span style="background-color: rgb(255, 251, 0);" class="">colossal disruption of the status quo</span>. It’s a desire to avoid that change — political, financial and otherwise — that drives many of the climate sceptics. <br class=""><br class=""><br class="">Still, as this journal has noted numerous times,<span style="background-color: rgb(255, 251, 0);" class=""> it’s clear that many policymakers who argue that emissions must be curbed, and fast, </span><span style="background-color: rgb(0, 253, 255);" class="">don’t seem to appreciate the scale of what’s required.”<br class=""></span><br class="">EDITORIAL<br class="">NATURE 21 FEBRUARY 2018<br class=""><br class=""><font color="#ff2600" class="">==================</font><br class=""><br class="">“...many scientists say deep emissions cuts are necessary … to prevent … dangerous consequences of global warming. <br class=""><br class="">"Getting from here to there would <span style="background-color: rgb(0, 253, 255);" class="">require a massive economic shift.”</span><br class=""><br class="">Rachel Pannett and Jeffrey Ball. “Australia Approves Energy Bill.” <br class="">The Wall Street Journal p.A7, August 21, 2009<br class=""><br class=""><br class=""><font color="#ff2600" class="">==================</font><br class=""><br class="">PNAS May 4, 2020<div class=""><br class="">Future [[ “colossal disruption ? LO ]] of the human climate niche<br class="">Chi Xu , Timothy A. Kohler, Timothy M. Lenton , and Marten Scheffer <br class=""><br class=""><b class="">OPEN ACCESS</b><br class=""><a href="https://doi.org/10.1073/pnas.1910114117" class="">https://doi.org/10.1073/pnas.1910114117</a><br class=""><br class=""><b style="background-color: rgb(255, 255, 255);" class="">Abstract</b><br class=""><span style="background-color: rgb(255, 255, 255);" class="">All species have an environmental niche, and despite technological advances, humans are unlikely to be an exception. Here, we demonstrate that for millennia, human populations have resided in the same narrow part of the climatic envelope available on the globe, characterized by a major mode around ∼11 °C to 15 °C </span><span style="background-color: rgb(255, 251, 0);" class="">mean annual temperature (MAT)</span><span style="background-color: rgb(255, 255, 255);" class="">. Supporting the fundamental nature of this temperature niche, current production of crops and livestock is largely limited to the same conditions, and the same optimum has been found for agricultural and nonagricultural economic output of countries through analyses of year-to-year variation. We show that in a business-as-usual climate change scenario, the geographical position of this temperature niche is projected to shift more over the coming 50 y than it has moved since 6000 BP. Populations will not simply track the shifting climate, as adaptation in situ may address some of the challenges, and many other factors affect decisions to migrate. Nevertheless, in the absence of migration, </span><span style="background-color: rgb(255, 251, 0);" class="">one third of the global population is projected to experience a MAT >29 °C </span><span style="background-color: rgb(0, 253, 255);" class="">currently </span><span style="background-color: rgb(255, 251, 0);" class="">found in only 0.8% of the Earth’s land surface</span><span style="background-color: rgb(255, 255, 255);" class="">, mostly concentrated in the Sahara. As the potentially most affected regions are among the poorest in the world, where adaptive capacity is low, enhancing human development in those areas should be a priority alongside climate mitigation.</span><br class=""><br class=""></div></body></html>