State of the Climate report – Experts respond

State of Climate report 2009The 2009 State of the Climate report by the US National Oceanic and Atmospheric Administration (NOAA), with contributions from the UK’s Met Office – released this morning is attracting substantial media coverage.

As part of a full review of global climate over the past year, the report includes information on data from 10 key climate indicators, including tropospheric (lower atmosphere) temperature, sea level, glacier mass and summer arctic sea ice. According to NOAA’s media advisory, the report involved more than 300 scientists in 48 countries (including NZ) and confirms that the world is warming, with the past decade the warmest on record.

The full report is available online at NOAA’s website.

New Zealand scientists have sent the Science Media Centre the following comments on the report:

Prof Martin Manning, Director –  Climate Change Research Institute, Victoria University of Wellington comments:

“The IPCC Assessment Report that was completed in 2007 concluded that the evidence for global warming had become unequivocal. The new study by about 300 scientists from many countries, including New Zealand, shows more evidence that this is the case.

“The importance of the report is that it provides a large amount of the details that lie behind our understanding that the Earth is warming. It does this without getting into the question of what is causing the change, and that is important because there needs to be greater recognition that much of climate science starts by clearly identifying the pervasive nature of the changes that are occurring.

“The global nature of these changes is summarised carefully in the report and its first graphic figure shows that every part of the world is being affected. It covers things like how lake levels are changing in much of the world; that oceans are warming to a depth of at least 700 meters; and patterns of changes in atmospheric pressure and wind flow. So much detail is provided that it also shows why no one person can keep track of all these aspects any more.

“The report does not cover some things like all the changes occurring in the major ice sheets, and it does put short term and long term changes together in a way that has to be kept in mind carefully when thinking about our future climate. However, because this report did not have the page limit that our IPCC report did, it provides much more of the evidence for recent climate changes. It also provides updates covering the last few years that make this evidence for an unequivocal global warming even stronger.”

Dr James Renwick, Principal Scientist, Climate Variability & Change, NIWA comments:

“This report, which takes a comprehensive look at the global climate system, and is made up of contributions from authors all around the world (including New Zealand), puts the facts on the table very clearly. All the key indicators show that the world is warming, and has been for decades. The trend is particularly clear in measures such as sea-level, which has been rising steadily for well over a century.

“There is a persistent myth in some quarters that “global warming stopped in 1998”. This report puts paid to such fallacies. The first half of 2010 shows record global warmth, and 2010 is set to be another very warm year overall.

“Given the quantity of carbon dioxide humankind has already emitted into the atmosphere, we are already committed to more warming and climate change. The time is now to make a real commitment to serious emissions reductions around the world, if we are to reduce the risk of very damaging levels of climate change this century.

“All the investigations into “climategate” and the research of high-profile climate scientists such as Phil Jones and Michael Mann have totally vindicated the science around climate change. That whole story was a fabrication, timed to interfere with the Copenhagen negotiations. Sadly, it worked, and we are now faced with an even harder job to reach a global consensus on action.”

Dr Glenn McGregor, Head of School of Environment at University of Auckland comments:

“The State of the Climate report provides yet more evidence via trends in a number of key climate change indicator variables, calculated by a number of independent climate science communities, that we are living in a period of rapidly changing climate circumstances. To what extent we can find a way to live with or adapt to these new circumstances such as the impact of atmospheric warming on human health and changes in oceanic heat on marine ecology and thus fisheries for example, presents us with one of the greatest challenges yet faced by society”

The following comments were gathered by our colleagues at the Australian SMC:

Professor Neville Nicholls is Professorial Fellow in the School of Geography and Environmental Science at Monash University and is President of the Australian Meteorological and Oceanographic Society:

“The NOAA report confirms, using many datasets, that the 2000s was the warmest decade in the observational record of global average temperature. And the warming has continued well into 2010, with the last twelve months (July 2009 to June 2010) the hottest “financial year” on record, in both the surface thermometer data and the completely independent satellite data. The warming trends in the satellite and surface thermometer data since 1979 (when the satellite data first became available) have been essentially identical, so don’t be fooled by anyone telling you that global warming is caused by the urban heat island effect or problems with thermometers – the satellite data don’t suffer from these issues. The NOAA report lists all the many, many data sets available and where you can obtain them. If you have doubts, go and check the data.”

Dr Karl Braganza is Manager of Climate Monitoring at the National Climate Centre in the Australian Bureau of Meteorology and is a contributing author of the State of the Climate report:

“The big climate event of 2009 was the strengthening El Niño event in the Pacific Ocean. Many Australian’s now understand that El Niño events are associated with dry conditions across large parts of the country. While this was true for most of the year, heavy rainfall fell across much of Eastern Australia during spring and into 2010. This apparently confounding situation is a timely illustration of the inherent unpredictability of Australian rainfall.

“Historically, El Niño events are also associated with warmer than average conditions in the lower atmosphere, particularly in the second half of the year for the Southern Hemisphere, and the following year for the globe as a whole. This is exactly what we observed, with Australia experiencing its second warmest year on record in 2009. Globally, temperatures during the first half of 2010 have been the warmest ever recorded.

“Breaking records with ever increasing frequency is symptomatic of the underlying warming of the climate system. 2009 ended the warmest decade on record, continuing a trend that stretches back over 70 years. As global warming continues, El Niño years will most likely continue to regularly rewrite the record books.

“One of the more important take home messages from the NCDC State of the Climate Report is that warming of the climate system is unequivocal, and is measured by much more than simply global mean temperature. This fact is probably less appreciated among the public than it should be. While the general media tends to focus on temperatures recorded by land based thermometers, with a tendency to overplay uncertainties in those observations, there are many other independent indicators that demonstrate that the world is warming, and that the warming is most likely due to greenhouse gas increases. These changes include warming in the oceans and in the upper atmosphere, as well as a host of impacts such as the rapid loss of Arctic sea-ice.”

Dr Lisa Alexander is a senior lecturer in the Climate Change Research Centre at the University of New South Wales and was a contributing author of Chapter 2 of the 2009 State of the Environment Report:

“The “State of the Climate in 2009” report indicates that average surface temperature estimates for the globe* in 2009 marked the end of the warmest decade in the instrumental record (i.e. since about 1870). The decadal warming has been particularly apparent in the mid- and high-latitude regions of the Northern Hemisphere although 2009 also ended Australia’s warmest decade since records began in 1910 (0.48degC above 1961-1990 average).

“In 2009, a transition from cooler than average tropical Pacific sea surface temperatures (La Niña conditions) to warmer than average conditions (El Niño conditions) dominated anomalies in many climate variables. This transition, which occurred during Southern Hemisphere winter, contributed to 2009 being ranked in the top 10 warmest years globally, and about 0.1°C warmer than 2008.

“The report also suggests that preliminary data indicate a high probability that 2009 will be the 19th consecutive year that glaciers have lost mass. Greenhouse gas concentrations continued to rise in 2009, with CO2 increasing at a rate above the 1978 to 2008 average.

“Some new satellite technologies for deriving weather and climate parameters have been introduced into the report for the first time, providing the exciting potential for further independent estimates of global surface temperature for example.”

*Principal estimates of global surface temperature are derived from the HadCRUT3 (UK), NOAA (USA) and NASA/GISS (USA) datasets.

For more information, or to contact any of the experts above, contact the Science Media Centre on tel: 04 499 5476 or email: