Weekly Science 23rd March
Here's our summary of the useful and interesting papers, letters
and commentaries that have been published over the past week in the
scientific literature...
Policymakers need to think in terms of probabilities
Climate change is evidently affecting plants and animals, but
according to a new scientific
commentary, there's too much focus on defining the contribution
of human-induced climate change to these biological responses.
According to the authors, Politicians in particular want to know
how much climate change is responsible for changes in biological
systems, but this can be difficult to determine as climate change
acts at the same time as other effects (both natural and
man-made).
They argue that untangling these competing effects is not the
most useful direction for research to take, and suggest that
research should focus on the interactions of climate change with
other factors, and on conservation of compromised species. Lead
author Camille Parmesan says (in an
interview with Nature):
"Yes, global warming is happening. Yes
it is caused by human activities. And yes we've clearly shown that
species are impacted by global warming on a global scale … What we
need to do now is focus on extensive field experiments and
observations to understand how multiple factors, such as
exploitation or habitat fragmentation, interact with a changing
climate to directly affect these species."
She also suggests that the policy makers need to take a less
black-and-white approach:
"We need to train policy makers to think
of probabilities and likelihoods and interactions. They don't like
it - but this is the accurate way to describe the science."
Ecosystem richness affects biomass production
Another large-scale biological study: a team of researchers in
Sweden have assimilated data from over 400 previous studies to
assess how the number of plant species within an ecosystem affects
the production of biomass in that ecosystem. More biomass
production means greater removal of CO2 from the atmosphere by
plants. The Swedes found
that the more biodiversity in a plant ecosystem, the more biomass
it produces - Keeping ecosystems healthy and diverse makes the most
of their CO2 drawdown abilities.
Causes of the Russian heatwave
This week sees the publication of an
article investigating the causes of the Russian heat-wave in
2010, and a previous heat-wave in 2003. The findings from this were
covered extensively a few weeks back. In both cases, the extreme
temperatures resulted from large and 'blocking' high-pressure
weather systems, most likely resulting from natural climate
variability.
Using high-resolution climate models, the researchers suggest
that similar heat-waves will be unusual in the next few decades.
However, they could become more common by the end of the century,
as the planet warms. We talked about this previously in our blog
about
extreme weather events and climate change.
Public perception of climate change
People with first-hand experience of the impacts of climate
change are more likely to be concerned about the issue, and be
willing to take mitigating action. This was the result of a UK
survey conducted in 2010, published in
Nature Climate Change this week. Of those questioned, those
who'd experienced flooding were less likely to view climate change
as a distant issue, and more likely to feel that their actions
could help to have an effect on climate change.
Climate model improvements
Climate scientists are always trying to update and improve their
models, which often tend to treat clouds as suspended water, and
ignore the effect of precipitating ice and snow. This week, a
study has been published which attempts to quantify the effect
of this assumption. The work finds that this assumption impacts on
the radiative heating and atmospheric circulation in climate
models.
Further work is needed to confirm the robustness of this finding
and to include the effects of precipitation as water, not just snow
and ice.