Land use factors distort temperature trends

Cities absorb more heat than rural areas. Copyright: Nasa

By: Katie Mantell

We encourage you to republish this article online and in print, it’s free under our creative commons attribution license, but please follow some simple guidelines:

You have to credit our authors.
You have to credit SciDev.Net — where possible include our logo with a link back to the original article.
You can simply run the first few lines of the article and then add: “Read the full article on SciDev.Net” containing a link back to the original article.
If you want to also take images published in this story you will need to confirm with the original source if you're licensed to use them.
The easiest way to get the article on your site is to embed the code below.

For more information view our media page and republishing guidelines.

The full article is available here as HTML.

Press Ctrl-C to copy

<div class="article-wrap">
<div id="article-introduction">
<h1>Land use factors distort temperature trends</h1>
<h4>By: Katie Mantell</h4>
</div>
<br />
<br />

<div id="article-body">
<p><P>Land-use changes such as the expansion of cities and changes in agriculture have more effect on climate change analysis than was previously thought, according to a new study.<BR><BR>Revised calculations published in this week’s <EM>Nature</EM> suggest that land-use changes are causing the Earth’s surface temperature to rise by about 0.27°C every century —  about twice as much as previous estimates. <BR><BR>Cities tend to be warmer than nearby rural areas because buildings absorb and retain heat. This ‘urban heat island’ effect means that temperatures are higher at urban monitoring stations than rural ones. Agriculture can also introduce biases, such as when irrigation increases heat retention in soil. <BR><BR>Researchers have been aware of these distorting effects on apparent temperature trends for some time, and have tried to correct temperature measurements accordingly. But these new findings suggest that such adjustments may have been insufficient.<BR><BR><a href="http://www.nature.com/login/scidev_login.taf?ref=/nature/journal/v423/n6939/full/nature01675_fs.html" target="_blank" onclick="pageTracker._trackPageview('/tracking/external/'+this.href);" rel="noopener noreferrer">Link to research paper in <EM>Nature</A><BR><BR></EM><a href="http://www.nature.com/nsu/030527/030527-6.html" target="_blank" onclick="pageTracker._trackPageview('/tracking/external/'+this.href);" rel="noopener noreferrer">Link to <EM>Nature Science Update</EM> news story</A> <BR><BR>Reference: <EM>Nature</EM> 423, 528 (2003)</P></p>

</div>
<div class="quick-links-wrapper">
<h3>You might also like</h3>
[related-articles]
</div>
<p>This article was originally published on <a href="https://www.scidev.net" target="_blank">SciDev.Net</a>. Read the <a href="https://www.scidev.net/global/news/land-use-factors-distort-temperature-trends/" target="_blank">original article</a>.</p>
<script type="text/javascript">
(function(e,t,n,r,i,s,o){e["GoogleAnalyticsObject"]=i;e[i]=e[i]||function(){(e[i].q=e[i].q||[]).push(arguments)},e[i].l=1*new Date;s=t.createElement(n),o=t.getElementsByTagName(n)[0];s.async=1;s.src=r;o.parentNode.insertBefore(s,o)})(window,document,"script","//www.google-analytics.com/ga.js","ga");var _gaq=_gaq||[];var _gaq=_gaq||[];_gaq.push(["_setAccount","UA-3223906-8"],["_trackEvent","article interaction","republished","https://www.scidev.net/global/news/land-use-factors-distort-temperature-trends/",null,true])
</script>
</div>

Land-use changes such as the expansion of cities and changes in agriculture have more effect on climate change analysis than was previously thought, according to a new study.

Revised calculations published in this week’s Nature suggest that land-use changes are causing the Earth’s surface temperature to rise by about 0.27°C every century — about twice as much as previous estimates.

Cities tend to be warmer than nearby rural areas because buildings absorb and retain heat. This ‘urban heat island’ effect means that temperatures are higher at urban monitoring stations than rural ones. Agriculture can also introduce biases, such as when irrigation increases heat retention in soil.

Researchers have been aware of these distorting effects on apparent temperature trends for some time, and have tried to correct temperature measurements accordingly. But these new findings suggest that such adjustments may have been insufficient.

Link to research paper in Nature

Link to Nature Science Update news story

Reference: Nature 423, 528 (2003)