The Marine Climate Change Impacts Partnership (MCCIP) has published its latest Report Card, involving a number of PML scientists. The report card provides the most comprehensive assessment yet on how climate change is affecting UK waters.
The report card explains how short term variability means some years will be cooler than others. However, long term records clearly demonstrate an overall warming trend in recent decades, which is expected to continue in the future.
For the first time, Arctic sea-ice coverage is considered by the report’s authors. A long-term decline is clearly apparent, with Arctic sea-ice extent retreating and the ice becoming thinner as temperatures rise. This may provide opportunities for European and Asian commercial ships to cross the globe via northern polar routes, but could herald other geopolitical challenges.
In addition, the 2013 report’s regional maps highlight differences across the UK’s seas and show the importance of local-scale impacts. For instance, the movement of fish species – important to commercial and recreational fishermen – and how non-native species are expanding their range are both covered.
Some key findings in the 2013 MCCIP Report Card include:
Temperature records continue to show an overall upward trend despite short-term variability. For example, in the last decade, the average UK coastal sea surface temperature was actually lower in 2008-2012 than in 2003-2007.
The seven lowest Arctic sea-ice extents in the satellite era were recorded between 2007 and 2013. The continuing downward trend is providing opportunities for the use of polar transit routes between Europe and Asia by commercial ships.
Changes to primary production are expected throughout the UK, with southern regions (e.g. Celtic Sea, English Channel) becoming up to 10% more productive and northern regions (e.g. central and northern North Sea) up to 20% less productive; with clear implications for fisheries.
There continue to be some challenges in identifying impacts of climate change. These are due to difficulties distinguishing between short-term variability and long-term trends, and between climate drivers and other pressures.
Dr Matthew Frost of the Marine Biological Association and Chair of the MCCIP Report Card Working Group said: "The marine environment is subject to a wide range of man-made pressures but can also change in response to natural processes. Disentangling these factors to enable identification of current and potential future impacts of climate change continues to be one of the greatest challenges facing marine scientists today. We have sought to clearly explain these challenges whilst continuing to report on the rapid and significant impacts of marine climate change."
Marine Environment Minister George Eustice said: "This report improves our understanding of how UK seas are already influenced by climate change and of potential changes in the future. Understanding these impacts, threats and opportunities is an essential basis for managing our marine environment."
The report card highlights how little is known about climate change impacts on the "marine economy", despite its importance for food (fish and aquaculture), energy (oil, gas and renewable energy), transport and coastal tourism and marine recreation. Coastal tourism and marine recreation is a key economic sector that could be highly sensitive to climate change (e.g. the threats of flooding, coastal erosion and opportunities for increasing visitor numbers), but little is known about future social and economic impacts.