Climate change is going to mean mosquito-borne diseases
spread north out of the tropics right? That seems to be the story the news media are giving us. But it is really the case? Do we really need to start thinking about buying bednets to protect against mozzy bites?
As editor of Global Health database I was invited to the ISNTD Bites
seminar in London, at the Natural History Museum where the issue was hotly debated. The session on climate change and disease vectors showed that
while biology of disease vectors like mosquitoes and sandflies is affected by temperature there are several other
factors that influence spread of disease vectors and the diseases they carry that may mean they don’t spread in the way straight climate maps predict.
Among these are land use, urbanisation and global trade. In fact, the
entomologists at the seminar were arguing that climate change issues are
distracting researchers from looking more into factors that are having drastic effects on the spread of disease vectors
and disease right now.
A disease of ash trees, first found in Poland in the 1990s (most reports suggest around 1992) but which has since spread through much of northern and central Europe, has been reported in the British countryside for the first time. The ash dieback disease was first reported in the UK in February 2012 in a consignment of infected trees sent from a nursery in the Netherlands to a nursery in Buckinghamshire, England. Since then, it has been found in a number of other sites in England and Scotland where young nursery trees have been received, but this week the disease has for the first time been found in the natural environment in East Anglia. The disease has devastated ash populations in other European countries, and now it is feared that it could do the same in Britain, where if it takes hold it could have similar impacts as Dutch elm disease had in the 1970s.
Climate change, high oil prices, and worries over dependence on imported fossil fuels, are just some of the reasons why governments have introduced policies to promote use of biofuels and other renewable energy sources in recent years. In the USA, the Renewable Fuel Standard requires a proportion of the corn harvest to be used for making biofuels, while in Europe there is an EU renewable energy target for transport fuel of 10% by 2020. But pressure groups such as Oxfam have argued that such targets promote a shift of agricultural land towards fuel rather than food production, driving food prices higher, and after the drought in the USA hit corn production this year the United Nations food agency (FAO) called on the United States to suspend its production of biofuel ethanol. This week, the EU has signalled a shift in biofuel policy to encourage energy production from waste rather than from food crops. However, while industry groups such as the Renewable Energy Association claim that the move will harm investment in biofuels, Oxfam says that the policy shift does not go far enough.
Glaciers and ice caps play an important role on earth’s climate; they
reflect 80-90% of incoming solar radiation; and they’re a major carbon sink,
especially in the Arctic, which accounts for up to 15% of the earth’s carbon
sink. As I reported in my previous blog, scientists alerted that the contribution of
glacial snow melt to the Himalayan river basins remains uncertain, due to a
lack of reliable and consistent data. Today, I came across a new study by
researchers from the Massachusetts Institute of Technology, just published in
the Journal of Physics D: Applied Physics, which provides new
clue to help us understand the reason for the fast rate of glaciers melting
witnessed in the past decades, if not centuries.
Around 1.3 billion people in the Himalayan river basins rely on both
snowmelt water from glaciers and monsoon waters to sustain their
livelihoods. In fact, seasonal snowmelt water from the Himalayan
glaciers is one of the main sources of freshwater reserves that directly
sustain people living in the region, especially in arid and semi-arid
areas, says an article in the September edition of the bulletin from the
UN Environment Programme (UNEP) Global Environmental Alert Service
(GEAS). However, the article alerts that the contribution of glacial
snow melt to the Himalayan river basins remains uncertain, due to a lack
of reliable and consistent data.
