Extreme drought in Europe worst since 2003

8/28/2015 , , , 0 Comments

This years summer (April-July) in central Europe have been one of rainless weeks and relentless heat, as expected from climate models. Similarly to the summer of 2003, a large part of the continental EU was affected by a severe drought in June and July 2015, as a consequence of the combination of rain shortages and very high temperatures which resulted in high plant water requirement (evapotranspiration) levels. France, Benelux, Germany, Hungary, the Czech Republic, northern Italy, and northern Spain experienced particularly exceptional dry conditions.

Agricultural production has suffered in large parts of central France, south-central Germany and into Poland, Hungary, Ukraine and southwards into northern Italy and Spain. Grain harvests in Germany have fallen 11% and apple harvests 21%, while France expect a 28% drop in corn output. Record low river water levels in Poland have revealed Jewish tombstones and Soviet fighter planes, as well as human remains from the second world war. 

Some parts of Germany have the lowest levels of soil moisture since records began in 1951. Restrictions to industrial and civil water use have been imposed. Monthly rainfall averages fell by as much as 80% in parts of France and northern Spain experienced daily temperatures over 30 degrees for more than 40 days.

Areas with the lowest soil moisture content since 1990 in July 2015 (in red) and in July 2003 (in blue). Source: European Drought Observatory

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Abrupt changes in ecosystems

8/17/2015 , , , , , 0 Comments

Credit: Lamiot (CC-BY-SA 3.0)

Ecological regime shifts

Human pressure on the planet's ecosystems have in some cases lead to gradual changes but more often it has lead to surprising, large and persistent ecological regime shifts. Such shifts challenges environmental stewardship because it leads to substantial changes in ecosystem services at the same time as these shifts are hard to predict and reverse.

A new study in PLOS now indicates that the most common drivers to ecological regime shifts include: climate change, agriculture and fishing. Aquatic systems, such as kelp forests, have been most affected by regime shifts. The good news, however, is that 62% of identified drivers can be managed at local or national scales, while only 38% can only be managed internationally.

Source: Rocha et al. (2015)

Food production and energy consumption major drivers 


According to the study, food production and climate change are key drivers of regime shifts that are coupled with one another and have the potential to lead to large-scale cascading effects. Food production relates to a number of negative drivers such as resource depletion, pollution, habitat destruction, and deforestation which have the potential to be managed locally or regionally. While climate change drivers needs to be managed internationally. 

Most drivers of ecological change are increasing along with the exponential growth of the world's economy. So while reducing local drivers of ecosystem change can build resilience to continued global change over the short term, global changes will eventually overwhelm local management. Indicating that it is necessary but insufficient to act only on a local to regional scale.

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Monster El Niño 2015/2016

8/11/2015 , , , , , 0 Comments

Warmer waters in eastern Pacific Ocean

Every 3-7 years variations in tropical winds and pressure shift warm ocean water east to the South American coast, causing an El Niño event. Last time we experienced a really strong El Niño was in 1997/1998 but this years event have the potential to top that record, according to many scientists. There is a 90% chance that El Niño will continue through the Northern Hemisphere winter 2015-16 (NOAA, 2015).

The map shows sea surface temperature anomalies in June 2015. We can see that there is a long patch of warmer waters off South Americas west coast stretching all the way to Indonesia. This is a typical characteristic of an El Niño event. We can also see the "blob", persistent warm patch, off North Americas west coast that has impacted California's drought condition.
This week average temperatures jumped to above 1.9C which is much sooner than most models predicted, that indicated it would occur by October/November. We could reach ocean warming of 2.2 or even 3C above average by the end of the year. Such temperature anomalies would exceed the maximum values seen during the record 1997/98 event.

Worse weather under current climate change?

Combining our current climate forcing with such a powerful El Niño could mean that global average atmospheric temperatures will continue to hit record highs. The heat coming from the Pacific Ocean is massive and will probably reinforce the the "hot blob" in the Northern Pacific as well as transport warmer waters into the Arctic, through the Bering Strait. This could increase the melting of Arctic sea ice with a reinforcing feedback of further warming in the region. A powerful El Niño could also increase storminess along the south and eastern US and across the North Atlantic where a cold pool south of Greenland (associated with a weakening North Atlantic current) is already intensifying storms.

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