November 13, 2013

expert reaction to the WMO provisional State of the Climate report

The World Meteorological Organization’s provisional annual statement on the Status of the Global Climate stated that 2013 is currently on course to be among the top ten warmest years since modern records began.

Dr Stephan Harrison, Associate Professor in Quaternary Science at the University of Exeter, said:

“The recent disaster in the Philippines has shown how vulnerable communities are being impacted by extreme weather events.  All the science says that such events are expected to get worse and more frequent.  

“The latest message from the WMO on global temperatures should therefore be another wake up call to politicians from the developed and developing world.  Current trajectories for adaptation and mitigation are wildly inadequate to meet the challenges of global climate change”.  

Dr David Reay, Senior Lecturer in Carbon Management at the University of Edinburgh, said:

“Year by year, decade after decade, our planet continues to warm.  The short-term spikes and troughs caused by ocean circulations make it easy to overlook the insidious spread of more and more heat through the world’s land, water and ice.  2013 is on course to be yet another new entry in the top ten warmest years ever recorded but, as global temperatures keep on rising, its chances of staying there are slim indeed.”

Professor Richard Allan, Professor of Climate Science at the University of Reading, said:

“The planet’s climate is hugely complex but thanks to increasingly realistic simulations and more comprehensive observations the human contribution to the warming of climate is becoming increasingly clear.

“In the last 40 years global surface temperatures have risen by 0.5 degrees C. This doesn’t sound much but is about 10% of the global temperature rise since the last ice age 20,000 years ago – when ice sheets covered parts of the UK.”

On the slowdown:

“Global surface warming has slowed over the last 15 years but heat has continued to accumulate within the oceans since 2000 – at a rate equivalent to each of the 7 billion humans on the planet using twenty 2kW kettles to continuously boil the sea.

“The most up-to-date research shows that natural fluctuations in the ocean have caused the heating from rising concentrations of greenhouse gases in the atmosphere to build up at deeper levels below the sea surface rather than the upper layers which influence surface temperatures.

“This is important since it provides evidence that the slowdown in surface warming is temporary and we can expect a return to substantial surface warming over the coming decades.”

On Arctic ice:

“Arctic ice volume has recovered slightly from the record minimum in 2012 yet the 5000 cubic kilometres of Arctic sea ice remaining in September 2013 is less than half the 1979-2012 September average – and it is obvious that the extent and volume have been diminishing rapidly over the last 30 years.”

On tropical storms:

“It is more likely than not that there will be an increase in intense tropical cyclone activity in the Western North Pacific and North Atlantic by the late 21st century.  This is based upon detailed simulations but also on basic physics: more ocean heat and greater quantities of moisture can increase their power and rainfall intensity; while changes in winds throughout the atmosphere and sea surface patterns which influence where Typhoons and Hurricanes will occur – and how severe they will be – are more difficult to pin down.”

Prof Sir Brian Hoskins, Director of the Grantham Institute for Climate Change, Imperial College London, said:

“This report highlights the continuing influence we are having on the world’s climate.  The levels of CO2 in the atmosphere are now about 40% higher than pre-industrial times, causing a substantial increase of the net amount of energy entering the Earth’s climate system.

“We can clearly see the impact this is having on rising sea levels, decreasing Arctic sea ice, and in the large number of high temperature records broken around the world.  The record super-typhoon in the Philippines came too late to be included in this report but is also an indicator of events that have become more likely in our changing climate.  In addition, the WMO have now said that 2013 appears to be on track to be one of the 10 warmest years since 1850.”

Prof Peter Wadhams, Professor of Ocean Physics at the University of Cambridge, said:

“The Philippines tragedy was made worse by the facts that sea level rise is leading to bigger flooding effects from storm surges, and that the rise in sea surface temperature worldwide is allowing a typhoon to build up higher energy levels.

“The report also states ‘the coldest years now are hotter than the hottest years before 1998’.  What they are saying is that despite interannual fluctuations (always jumped upon by climate sceptics) the trend is so strongly upwards in temperature that even hot years in our memories (e.g. summer 1976 in the UK) are – when globally averaged – actually cooler than even the coolest year in our present era.”

Prof Jonathan Gregory, Climate Researcher at the University of Reading, said:

“Thanks to satellite observations over recent years, we now have much improved estimates – not only of the rate of global mean sea level rise, but what is contributing to it.  The sum of these contributions agrees with what we observe in the real world, so we are very confident that we can account for this trend in sea level rise as being the result of thermal expansion (as the ocean water warms up) and ice loss on land (from glaciers and ice sheets).”