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Making a film about climate change is difficult, especially if you want it to reach a wide audience. One problem is the long time scale of climate change, which fits badly with the time scale of a typical film narrative. That was the reason why in the Hollywood blockbuster The Day After Tomorrow some laws of physics were treated with a certain artistic freedom, in order to present a dramatic climate change within a few weeks instead of decades.
Mike and I have spent the last few days at a very interesting workshop in Iceland, where climate scientists, social scientists and filmmakers were brought together in conjunction with the Reykjavik International Film Festival. I will make no attempt to reproduce the many exciting discussions which we had, that often continued into the night. Instead, I’d like to present two short films by workshop participants. I chose a contrast of hot and cold.
First, the cold. The following film is a trailer by Phil Coates, a British filmmaker and expedition leader, who has filmed in extreme conditions on all seven continents. It is a “work in progress” under the working title “North Pole Living on Thin Ice”. Coates was dropped off with three scientists on the sea ice near the North Pole. On foot out on the Arctic Ocean they made oceanographic and ice thickness measurements. Soon you will be able to experience this research expedition on film. The scientific findings of the team will of course come out in the scientific literature.
The time has come: the new IPCC report is here! After several years of work by over 800 scientists from around the world, and after days of extensive discussion at the IPCC plenary meeting in Stockholm, the Summary for Policymakers was formally adopted at 5 o’clock this morning. Congratulations to all the colleagues who were there and worked night shifts. The full text of the report will be available online beginning of next week. Realclimate summarizes the key findings and shows the most interesting graphs.
Update 29 Sept: Full (un-copyedited) report available here.
It is now considered even more certain (> 95%) that human influence has been the dominant cause of the observed warming since the mid-20th century. Natural internal variability and natural external forcings (eg the sun) have contributed virtually nothing to the warming since 1950 – the share of these factors was narrowed down by IPCC to ± 0.1 degrees. The measured temperature evolution is shown in the following graph.
Figure 1 The measured global temperature curve from several data sets. Top: annual values. Bottom: averaged values over a decade.
The heat content of the oceans is growing and growing. That means that the greenhouse effect has not taken a pause and the cold sun is not noticeably slowing global warming.
NOAA posts regularly updated measurements of the amount of heat stored in the bulk of the oceans. For the upper 2000 m (deeper than that not much happens) it looks like this:
Change in the heat content in the upper 2000 m of the world’s oceans. Source: NOAA
Recently a group of researchers from Harvard and Oregon State University has published the first global temperature reconstruction for the last 11,000 years – that’s the whole Holocene (Marcott et al. 2013). The results are striking and worthy of further discussion, after the authors have already commented on their results in this blog.
Guest post by Anders Levermann [via The Conversation]
Small numbers can imply big things. Global sea level rose by a little less than 0.2 metres during the 20th century – mainly in response to the 0.8 °C of warming humans have caused through greenhouse gas emissions. That might not look like something to worry about. But there is no doubt that for the next century, sea level will continue to rise substantially. The multi-billion-dollar question is: by how much? More »
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