Climate - the game changer?

'Climate change' is a phrase thrown about by the media and scientists, commonly used to explain the weird and wonderful things that are happening on Earth today. But what affect is it having on Invasive Alien Species?

What does 'climate change' mean?

According to the Metoffice, climate change is:

"A large-scale, long-term shift in the planet's weather patterns or average temperatures."

and the results of this can be seen across the world. For instance, since 1901 there has been a 0.89 degree Celsius rise in the average surface temperature, global sea levels have risen 19cm since the 1900's, rainfall patterns are changing with a major increase in the mid-latitudes of the Northern Hemisphere and Arctic sea ice has reduced 4% since the 1970's.
These telltale signs of climate change, amongst many others, have major impacts on all organisms. But what affect is it having on Invasive Alien Species? Hellmann et al. defined five key consequences that climate change is already having or is expected to have in the future. 

1. Altered transport and introduction methods: 

As previously mentioned in my blog 'Transport and Trade of Invasive Alien Species', how Invasive Alien Species get to new areas is really important. Not only is it changing due to increased transport efficiencies but rises in sea levels mean previous unconnected areas are being joined by water. Also, melting of sea ice means that new shipping routes are becoming available and shipping seasons are being extended meaning more opportunity for pesky species to hitch a ride. 

2. New Invasive Alien Species: 

Non-native species that were not previously unsuccessful at invading, may be able to inhabit new areas that now have climates more suitable to them. Also, Invasive Aliens Species are known to be able to be able to survive in changing environments, where are native species are not as good. With longer dispersal ranges, more tolerances and a shorter juvenile period they are more likely to survive when the going gets tough! 

3. Altered impact of the previous Invasive Alien Species:

The impact an Invasive Alien Species can have, once fully established in an area, is commonly restricted by environmental factors such as temperature and water. For instance, a temperature constraint set by the extreme cold may mean an Invasive Alien Species is unable to survive in winter, allowing the native species to recover and spread. However, with temperature increases, the growing season may be extended, reducing the recovery time of the native species and could result in their extinction. 

4. Altered distribution of the previous Invasive Alien Species:

With changes in climate, the landscapes also change, and the spread of Invasive Alien Species responds to this. Bellard et al. for example, predict that species are likely to move away from lower latitudes due to the already extreme climatic conditions that are likely to become unbearable. This is expected to lead to a loss of tropical Invasive Alien Species but a movement to more temperate mixed forest areas in the Northern Hemisphere. Its already being seen with a reported 76% increase in the number of Invasive Alien Species in Europe in the last 30 years. 

5. Change to the effectiveness of control strategies: 

Check back soon to find out more about this and how scientists and governments are trying to combat the issue of Invasive Aliens Species through control, such as the chemical spraying shown to the right. 

So why is all this climate change occurring? Click the link to find out some more information: http://www.metoffice.gov.uk/climate-guide/climate-change/why

Also, to find out how climate is affecting human health, check out this other blog https://unhealthyplanet.blogspot.co.uk!