Monday, February 22, 2010

Climate change impacts from an ecosystem perspective

Some food for thought with these extracts from a national conference about climate change (Bojanala 2005), which focused on ecosystem impacts:

Climate Change and African Tropical Coral Reefs:

...David Obura, Coral Reef Degradation of the Indian Ocean (Kenya) said the first major regional signal regarding the impacts of climate change on coral reefs was the 1982-83 ENSO in the eastern Pacific, while the 1997-98 ENSO provided the first major global signal of change. He identified the major impacts on coral reefs as changes in ocean current and processes, increased sea surface temperature and solar radiation, sea level rise, and the acidification of sea water. He said that coral bleaching affects the whole reef ecosystem, as well as related ecosystem services, and noted that 10% of the world’s coral reefs have already been impacted by climate change. He underscored that the loss of coral cover results in a loss of livelihoods for reef communities. Regarding the vulnerability of African reefs, he noted that by 2015 catastrophic bleaching would take place every 5 years in East Africa. Regarding policy options and actions, he emphasised the need for local responses and management, and monitoring and research, including climate vulnerability studies.

Biodiversity Responses in the Southern Ocean African Islands:

In his presentation, Steven Chown, University of Stellenbosch (South Africa), stressed the effects of climate change on interactions between indigenous and invasive species. He said that invasive species grow faster under warmer conditions than indigenous species. He also said that climate change was already ‘promoting’ invasive species over indigenous species. He also noted that the interaction between biological invasions and climate change has not been sufficiently addressed.

Droughts in South Africa are becoming Longer, More Intense and More Frequent:

Is it a boost from Climate Change? In his presentation, Tiba Kabanda, University of Venda (South Africa), provided a case study of droughts in the Limpopo Province in South Africa between 1960 and 1999. He po
inted out an increase in rainfall from 1960 to 1980’s, followed by a negative trend up until 2000. Using the case study, he illustrated the evolution of spatial patterns of drought as well as changes in intensity. He suggested that increases in the distribution and intensity of drought could be attributed to an increase in sea surface temperatures in the Indian Ocean, therefore decreasing the amount of moisture affected inland, which would normally provide this semi-arid region with rainfall. In addition to this, ENSO and QBO events may disturb the rain-producing systems in the area.

Species Migration under Climate Change:

This presentation was co-authored by Pam Berry, Oxford University and Richard Pearson, American Museum of Natural History. In his presentation, Richard Pearson said fossil evidence illustrates large-scale species shifts, indicating that migration is one of the key responses to climate change; however, he said these changes are occurring more rapidly and can be due to a climate change signal. He highlighted the consensus in the scientific community of a poleward shift however; he said difficulties lie in projecting present climate situations for the future as well as the parameterisation of models. He stressed the importance of providing suitable climate space for species to shift, but said these shifts will be species dependent, and may result in global species extinction. He stressed the importance of clustering small reserves to ensure species homogeneity and dispersal, as well as providing dispersal corridors. He also highlighted the importance of decisions regarding conservation policies in protected areas.

Detecting and Monitoring Climate Change Impacts in Arid Ecosystems:

.....In her presentation, Wendy Foden, South African National Biodiversity Institute, presented the major findings of SANBI research on the Kokerbome or quiver tree. She noted that there is large scale dieback of kokerboom at the equatorward and low altitude parts of its range and an increase in abundance of kokerboom at poleward and high altitude parts of its range. This is a clear sign of the early stages of a poleward range shift in response to climate change. She also showed that significant increases in temperature have been experienced in Namibia and the northern Cape over the last 24 years, with a mean temperature increase of 0.2 degrees per decade in the region, showing a clear relationship between the declining soil water availability and kokerboom mortality. This study of the kokerboom provides a unique opportunity to ground truth conventionally climate change models. Comparison between actual and modelled kokerboom mortality shows that modelled mortality is fairly conservative and does not overestimate the threat from climate change. She expressed concern over the absence of signs of new populations and recruitment, as this would be expected in response to climate change. She concluded that sedentary, slow dispersing species like plants may not be able to disperse fast enough to keep up with climate change. This has important implications for ecosystems throughout the world and may have serious implications both for further modelling as well as for future global biodiversity. Finally, she suggested that, contrary to popular belief, desert ecosystems are not well prepared for global warming as the species within them may already be at the limits of their climatic tolerance. This study is one of the first to examine climate change impacts in Africa, and the first to examine the entire range of a sedentary desert species.

5 Opinion(s):

Anonymous said...

How about we blame "climate change" to exactly wht it is - climate change. Since the begining of the world, there has been natural climate change. I don't understand why these scientists/environmentalists now want to jump up an down and blame everyone but Mother Nature. Hundreds of years ago there wasn't snow on the Alps - now there is. Glaciers melt and others form. Enough about this man-made farce. Most of the science has been disproved and Phil Jones has admitted that they manipulated the data. This farce is over. The way forward is to stop giving countries money to breed and feed when they can't do it themselves. Nature would've taken these breeds out by now. India and China should stop having babies. Have you ever wondered how they keep 2.5billion alive daily. Where does all their waste go? How about asking these questions and leave the climate alone to do it's thing...

Anonymous said...

I see the focus is on climate change now, rather than on the farce that global warming has turned out to be.

What they wanted to do with global warming was to say that it is caused by man and thus some men had to pay other men because of it. Global warming was chosen to be the vehicle to create a global taxation scheme. The only problem was that the science did not correspond to what the globalist taxation creators desired.

Now they have moved the focus away from global warming - because the truth about the global warming lie was exposed - to climate change.

Ice age - it warms up - ice age.

Fact is that climate change happens all the time.
The planet has been cooling for the past 15 years. Oh, that is climate change. Great bring on the global tax. hahaha

Bah

In order to tax people for climate change they will have to proof that climate change is caused by humans and that is like trying to proof the world flat.

FishEagle said...

Anon, why can't we work on improving our air pollution AND stop giving countries money to breed and feed? The environmental damage from over population is reason to stop that charity.

Anonymous said...

@FE

I agree.
What I said was that global warming as caused by mankind is a lie to create revenue.

We still however have to focus on lessening pollution in general. I only wish that the elites would stop trying to hijack the green movement in order to further enrich themselves.

Anonymous said...

a few yrs ago i was in mocambique. much to my dismay, i saw that every coral reef had been destroyed by dynamite fishing. the entire world didnt give a chit. now that coral bleaching has been observed, the alarmists shout "global warming", even though it is proven that bleaching is a result of el nino, not CO2 emissions. Any excuse for a global tax...