What appears at first glance to be a 'pause' in the warming of the climate has prompted much discussion in the media (and some 'I told you so' crowing from deniers) but can we really all heave a collective sigh of relief, assume we have dodged the climate bullet and get on with worrying about something else?
1998 was the hottest year on record according to surface temperature records and no year since has been hotter. This has caused some speculation that global warming has 'stalled'. But 1998 was far from a typical year. An abnormally strong El Nino caused heat to transfer from the Pacific Ocean to the atmosphere. Consequently, we experienced above average surface temperatures. However, when scientists 'remove' the El Nino effect the trend from 1998 to 2007 is still one of warming.
This is not the full story though. Although global surface temperatures are generally used as a proxy for measuring the progress of global warming, 'real' global warming is far broader than this and includes the heat taken up by the oceans (which also melts sea ice) and the heat which melts ice on the land. Over 70% of the Earth's surface is actually ocean and around 93.4% of global warming has gone into heating the oceans. How that heat is then distributed and exchanged with the atmosphere is down to natural cycles that we are still learning about.
The global energy balance – the balance between incoming energy from the Sun and outgoing heat from the Earth – is what ultimately regulates our climate. The planet is currently in a 'positive energy imbalance' – more energy is coming in than radiating back into space – as a result of heat-trapping greenhouse gases from human activities. This energy imbalance is what is causing global warming.
Current scientific thinking is that in recent years, for reasons that are not fully understood, proportionally more heat has been taken up by the oceans. The excess heat has also gone into the melting of Arctic summer sea ice and glacier and ice cap retreat. Ice loss in all of these icy domains is accelerating. In short both land and sea have seen substantial warming, even though this is not necessarily reflected in the surface air temperatures.
In summary, global warming hasn't 'stopped', 'paused' or 'stalled'. Surface temperatures are still rising, albeit more slowly than at some points in the past. But with all the heat currently lurking in the ocean, surface warming could speed up again at any time.
So, we are not off the hook. Greenhouse gas emissions continue to rise and continue to affect the global climate, risking catastrophic impacts to ecosystems and communities.
The fossil fuel industry and the governments that support and enable it are still planning 14 massive coal, oil and gas projects that would produce as much new carbon dioxide (CO2) emissions in 2020 as the entire US, and delay action on climate change for more than a decade, as the Greenpeace International report, Point of No Return, shows.
The global renewal energy scenario developed by Greenpeace – the Energy [R]evolution – shows we can deliver the power and mobility these dirty projects are promising without the emissions and the destruction ... not only faster, but also at a lower cost. But the clean energy future made possible by the development of renewable energy will only become a reality if governments rein in investments in dirty fossil fuels and support renewable energy.