Tuesday, 20 January 2015

Humans push planet beyond boundaries towards "danger zone": study

ROME (Reuters) - Human activity has
pushed the planet across four of
nine environmental boundaries,
sending the world towards a
"danger zone", according to a
study published on Thursday in
the journal Science.
Climate change, biodiversity loss,
changes in land use, and altered
biogeochemical cycles due in
part to fertilizer use have
fundamentally changed how the
planet functions, the study said.
These changes destabilize
complex interactions between
people, oceans, land and the
atmosphere, said the paper
"Planetary Boundaries: Guiding
human development on a
changing planet" by 18 leading
international researchers.
Passing the boundaries makes
the planet less hospitable,
damaging efforts to reduce
poverty or improve quality of life.
"For the first time in human
history, we need to relate to the
risk of destabilizing the entire
planet," Johan Rockstrom, one of
the study's authors and an
environmental science professor
at Stockholm University told the
Thomson Reuters Foundation.
Scientists in 2009 identified and
quantified the nine planetary
boundaries within which
humanity can develop and thrive.
The five other boundaries -
ozone depletion, ocean
acidification, freshwater use,
microscopic particles in the
atmosphere and chemical
pollution - have not been
crossed.
Passing the boundaries does not
cause immediate chaos but
pushes the planet into a period
of uncertainty.
Scientists consider climate
change the most serious crossed
boundary.
The amount of carbon dioxide in
the atmosphere, a gas causing
the planet to warm, has
exceeded 350 parts per million
to the present 395 parts per
million, crossing the boundary of
what scientists think to be
acceptable.
"We are at a point where we may
see abrupt and irreversible
changes due to climate change,"
Rockstrom said, as warming
could cause Arctic ice sheets to
melt releasing more greenhouse
gases and creating a vicious
feedback loop.
The study results are set to be
incorporated into the new global
development goals that will be
finalised in September at the
United Nations in New York to
replace the Millennium
Development Goals on poverty
alleviation expiring this year.
Scientists hope the new study
will help balance competing
demands for economic growth
and environmental sustainability
which are likely to arise during
the conference.
Despite a steady drumbeat of
grim warnings, food prices have
declined the past four years,
indicating that wild weather
linked to climate change is not
destroying harvests worldwide.
Commodity prices, a measure of
scarcity for energy and other
basic goods, are also falling,
leading some economists to
question warnings from climate
scientists and environmentalists.
"Just because we are not seeing
a collapse today doesn't mean
we are not subjecting humanity
to a process that could lead to
catastrophic outcomes over the
next century," Rockstrom said.

No comments: