Dry, cracked earth during a drought.

Future droughts will be influenced by climate change.

Climate questions: Has global warming stopped?

All measurements of the climate system indicate the long term warming trend is continuing. It is inappropriate to use short term data sets to determine long term trends.

  • 1 June 2011 | Updated 22 March 2013
  1. In brief
  2. In detail

In brief

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Hot Topics David Jones

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Transcript

When we look at global warming – and what we look for is patterns over the long term, so not the patterns from year to year, but the trends that we have over decades or centuries – what we’ve seen in global temperature trends is one of a warming trend, so we’re seeing warming at about .15 degrees per decade for global temperatures, and what that means is over the course of the last century we’ve now seen about one degree of global warming.

Global warming clearly hasn’t stopped. When we look at our planet, the last decade has been the warmest on record. Nine of the ten warmest years have been in the last decade, and we know the warmest year on record was 2010, so clearly global warming hasn’t stopped.

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Variations in global-average temperature over the past century can be measured in the near-surface air, the lowest 10 km of the atmosphere (the troposphere) and in the ocean.

All measurements indicate a long-term warming.

The surface of the Earth has warmed by about 0.74 ˚C since the start of the twentieth century.

This long-term warming trend is overlaid on short-term fluctuations due to such factors as El Niño and La Niña.

Data over the past decade provide little insight into long-term trends; the period is simply too short.

Nevertheless, the past decade has been the warmest in the instrumental record.

Sea surface temperatures and ocean heat content for the upper 300m and 700m of the ocean show long-term warming.

Global average sea level has risen by 17cm during the 20th century.

Disclaimer

Based on information written by CSIRO on behalf of the Department of Climate Change http://www.climatechange.gov.au/climate-change/~/media/publications/science/hot-topics-globalwarming-v2.ashx [external link] and modified to reflect recent research findings. Published with permission of the Department of Climate Change.

References

Cazenave A and Llovel W. 2010. Contemporary Sea Level Rise. Annual Review of Marine Science. 2: 145-173.

Church JA and White NJ. 2011. Changes in the rate of sea-level rise from the late 19th to the early 21st Century. Surveys in Geophysics. Submitted.

Domingues CM, Church JA, White NJ, Gleckler PJ, Wijffels SE, Barker PM, Dunn JR. 2008. Improved estimates of upper-ocean warming and multi-decadal sea-level rise. Nature. 453.

Easterling DR, Wehner MF. 2009. Is the climate warming or cooling? [external link]. Geophysical Research Letters. 36. L08706.

Fawcett R. 2008. Has the world cooled since 1998? Bulletin of the Australian Meteorological and Oceanographic Society. 20: 141-148.

IPCC. 2007. Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt KB,Tignor M, Miller HL. Eds. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.

Kaufmann R, Kauppi H, Mann M and Stock J. 2011. Reconciling anthropogenic climate change with observed temperature 1998–2008. PNAS.

Thorne et al. 2010. Tropospheric temperature trends: history of an ongoing controversy. WIREs Climate Change. DOI: 10.1002/wcc.80.

WMO. 2011. 2010 equals record for world’s warmest year [external link]. World Meteorological Organisation Press Release. No. 906. World Meteorological Organization. Geneva.