ECOSYSTEMS
The
climate changes the planet is currently undergoing, and the threats
posed by greenhouse gases, all interlink with the entire planet's
ecosystems which have been carefully balanced for millennia. Since the
industrial age, this has changed, and the way we now exploit the
Earth's resources affect everything in the chain. Forests, wetlands and
oceans have absorbed carbon forever - now with mining, eradicating
forests for agriculture etc., these gasses are building in the
atmosphere and can endure there for a century permitting
ever-increasing rises in temperature, which in turn leads to ice-melt
and rising sea-levels. While world governments and individuals confront
how to reduce energy levels which result in CO2 emissions, the
ecosystems also need to be considered. Deforestation alone can add more
of a threat to global warming than all the cars on the planet's
roads. It's
unfortunately a very complex subject, difficult to summarize in a few
short paragraphs. It has been necessary for us, then, to give more
attention to each of the major ecosystem issues where we can learn what
went wrong, and what must be done to mitigate a looming crisis.
______________________________________________________ Latest report: More
carbon is stored in soil than in the atmosphere and plants combined. (May 2013) Returning
carbon to where it belongs, in the soil, represents
not only our greatest opportunity to reduce atmospheric CO2 levels, but
simultaneously enhances soil fertility and biodiversity, and the land's ability
to retain water. We get the impression that human interference with climate is
a sky thing: those greenhouse gases we keep pumping into the air. But it's also
a ground phenomenon. The
flip-side of rising atmospheric CO2 is the loss of carbon in the soil, the main
component of soil organic matter. Over time, more CO2 has entered the
atmosphere from soil-disturbing agricultural practices than the burning of
fossil fuels. Once we understand
this, and encourage land management strategies that store carbon as opposed to
promoting its oxidation, things look different. This is cause for optimism
because while we can't un-burn fossil fuels (futuristic geoengineering tricks
notwithstanding), we can effectively return carbon to the soil. According to
Rattan Lal, Distinguished University Professor at the Ohio State University,
who speaks widely on the topic, soil-carbon restoration can potentially store
about one billion tons of atmospheric carbon per year. This would offset around
8-10% of total annual CO2 emissions and one-third of annual enrichment of
atmospheric carbon that would otherwise stay in the air. link
May 14, 2013: Desertification
and sustainable land management Land degradation – more specifically drought
and desertification – have become increasingly pressing problems for a growing
number of countries around the world. High-level
representatives from 195 nations will gather in Windhoek, Namibia from
September 16-27, 2013 for the 11th bi-annual Conference of Parties) to review
implementation of the U.N. Convention to Combat Desertification. Meeting for the first time in southern
Africa, UNCCD delegates will review implementation of the convention to date
and plan for the ensuing two years of programs and actions. Desertification, along with climate change and the loss
of biodiversity, were singled out as the greatest challenges to sustainable
development at the 1992 Rio Earth Summit. Severe land degradation is estimated to be
affecting 168 countries around the world.
link
The
four links below each lead to a page for further reading
The importance of permafrost. (November 2012)
Permafrost is the soil in high latitudes that stays frozen
year-round. It occupies nearly 24% of the land in the Northern Hemisphere. In
order to qualify as permafrost, the soil temperature must remain below 32°F for
at least two years, but there are thick seams of permafrost that have remained
solid for thousands of years. While a few inches of topsoil tends to thaw in
the summer (even in arctic regions), the UNEP report estimated that a global
temperature increase of 5.4°F would lead to a 10.8°F increase in temperature in
the Arctic, which would result in a loss of up to 85% of surface-level
permafrost. A loss of that scale would have severe ecological and economic
impacts. Those range from the increased frequency of rockslides, to the
destruction of infrastructure built on the once-solid ground. Permafrost
emissions could ultimately account for up to 39% of total emissions and should be factored in to treaty negotiations expected
to replace the Kyoto Protocol. (UNEP
estimates that 1700 gigatonnes of carbon, twice that currently in the
atmosphere, could significantly amplify global warming should thawing
accelerate as expected. Currently permafrost thaw is not included in
any climate models used by the IPPC.) link
Understanding sea level - sea-level
isn’t level seas. Although sea level rise might, at first glance, seem to be a
relatively easy subject to grasp, much of the misunderstanding that exists in
the blogosphere can be put down to the flawed notion that the sea behaves like
water in a swimming pool, or bathtub. In reality the Earth’s surface (lithosphere)
is elastic and deformable which contributes to a complicated picture where
local sea level might be somewhat different than the global sea level
trend. The term Glacial Isostatic
Adjustment describes the deformation of Earth’s surface from
the growth and decay of giant ice sheets over time, or more specifically, from
the exchange of mass, in the form of water or ice, between the continents and
ocean during the ice age cycles. The planet-wide changes which result
from this loading and unloading are due to the Earth’s lithosphere
wanting to reach equilibrium (isostasy). link
Seagrass – an important carbon sink – under threat
It turns out that
seagrass ecosystems hold as much carbon per hectare as the world's forests –
and are now among its most threatened ecosystems. In the past century, 29% of
seagrass has been destroyed globally, mostly by water pollution, dredging for
new developments, and climate change. With seagrass meadows disappearing at an
annual rate of about 1.5%, 299 million tonnes of carbon are also released back
into the environment each year. Piecing together old and new data from 946
seagrass meadows around the world, an international team of researchers
estimated that seagrass captures 27.4 million tonnes of carbon each year,
burying it in the soil below. And unlike forests that hold carbon for about 60
years then release it again, seagrass ecosystems have been capturing and
storing carbon since the last ice age. That means that up to 19.9 billion
tonnes of carbon are currently stored within seagrass plants and the top metre
of soil beneath them – more than twice the Earth’s global emissions from fossil fuels in 2010. link (What is seagrass?)
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March 2012: Holding back the Sahara with 4,300 miles of trees. Africa
is turning to desert. Studies show that as much as two-thirds of the continent’s
arable land could become desert by 2025 if current trends continue. But a bold initiative
to plant a wall of trees 4,300 miles through 11 African nations from coast to
coast could keep back the sands of the Sahara, improve degraded lands, and help
alleviate poverty. link
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October 2012: 850 billion tons of carbon stored in frozen
Arctic ground could be released. As much as 44 billion tons of nitrogen and 850
billion tons of carbon stored in arctic permafrost, or frozen ground, could be
released into the environment as the region begins to thaw over the next
century as a result of a warmer planet, according to a new study led by the
U.S. Geological Survey. This nitrogen and carbon are likely to impact
ecosystems, the atmosphere, and water resources including rivers and lakes. For
context, this is roughly the amount of carbon stored in the atmosphere today.
link May 2012: World’s aquifer depletion leads to rising sea-levels. Humanity's
unquenchable thirst for fresh water is driving up sea levels even faster
than melting glaciers, according to new research. The massive impact of the
global population’s growing need for water on rising sea levels is revealed in
a comprehensive assessment of all the ways in which people use water. Trillions
of tonnes of water have been pumped up from deep underground reservoirs in
every part of the world and then channelled into fields and pipes to keep
communities fed and watered. The water then flows into the oceans, but far more
quickly than the ancient aquifers are replenished by rains. The global tide
would be rising even more quickly but for the fact that man-made reservoirs
have, until now, held back the flow by storing huge amounts of water on land. Water
taken from deep wells is geologically old – there is no replenishment and so it
is a one way transfer into the ocean. Over the past half century 18 trillion
tonnes of water has been removed from underground aquifers without being
replaced. In some parts of the world, the stores of water have now been
exhausted. link August 2012: Earth continues to lend a helping hand to decrease emissions. The
carbon soaked up from the atmosphere by the seas and by plants and soil
on land rose to an estimated 5 billion tonnes in 2010 from 2.4 billion
in 1960, according to the findings by a team of U.S. scientists. Over
the 50-year period, nature had soaked up 55% of mankind's greenhouse
gas emissions that totalled 350 billion tonnes, mostly CO2 from burning
fossil fuels. link January 2012: If our ecosystem were a valued commodity. Some
of the world's poorest people would be half a trillion dollars a year better
off if the services they provide to the rest of the planet indirectly – through
conserving natural habitats – was given an economic value, a new study has
found. Many of the valuable habitats and species preserved in some of the
world's key biodiversity hotspots are under threat. But the
people who live in these areas lack the means to improve their conservation efforts
according to a new study in the journal BioScience. If poor people were paid
for the services they
provide in they could reap $500bn. There are some fledgling schemes that could
help to raise this cash, for instance, the United Nations-backed system called
Redd (Reducing Emissions from Deforestation and forest Degradation), which uses
carbon trading to generate cash to preserve trees, but so far they are small in
scale. link |
October 2010: UN
says biodiversity loss greater financial risk than terrorism. The financial
risks posed by the loss of species and ecosystems have risen sharply and are
becoming a greater concern for businesses than international terrorism. From
over-depletion of fish stocks and soil degradation caused by agricultural
chemicals to water shortages and mining pollution, the paper, commissioned by
the UN Environment Programme, said the
likelihood has climbed sharply that declines in biodiversity would
have a "severe" $10bn to $50bn impact on business. link
July 2011: Between
1850 and 1970 agriculture contributed most CO2. Over the past 150 years,
between 50% and 80% of organic carbon in the topsoil has vanished into the air,
and seven tons of carbon-banking topsoil have been lost for every ton of grain
produced. On close inspection, it seems that the problem isn't the carbon itself,
it's that there's too much in the air and not enough in the ground. When we
consider our CO2 predicament, we tend to fault our love affair with the car and
the fruits of industry. But the greater culprit has been agriculture: since
about 1850, twice as much atmospheric CO2 has derived from farming practices as
from the burning of fossil fuels (the roles crossed around 1970). So, how do we
get that carbon out of the air and back into the soil? Some suggest placing
calcium carbonate or charcoal (aka "biochar") directly into
agricultural soil. But a growing number of soil and agricultural scientists are
also discussing a low-tech, counterintuitive approach to the problem that
depends on a group of unlikely heroes: cows. The catalyst for reducing CO2 and
restoring soil function and fertility, they say, is bringing back the roving,
grazing animals that used to wander the world's grasslands. The natural
processes that take place in the digestive system and under the hooves of
ruminants might be the key to turning deserts back into grasslands and reversing
climate change. In other words, a climate-friendly future might look less like
a geo-engineered landscape and more like, well, "Home on the Range." link
April 2011: New estimates on ecosystem's ability to sequester carbon. A research group has concluded that forests and other terrestrial
ecosystems in the lower 48 states can sequester up to 40% of the nation's
fossil fuel carbon emissions, a larger amount than previously estimated. That's
substantially higher than some previous estimates, which indicated these
ecosystems could take up the equivalent of only about 30% of emissions or less.
There's still some uncertainty in these data, but it does appear that the
terrestrial carbon sink is higher than believed in earlier studies. However,
the scientists cautioned that major disturbances, such as droughts, wildfires
and hurricanes, can all affect the amount of carbon sequestered in a given
year. Large droughts that happened twice in the U.S. in the past decade reduced
the carbon sink about 20%, compared to a normal year. link July 2011: Jellyfish shut down nuclear plants. A nuclear
power station in Israel is shut down by jellyfish, a day after a nuclear
facility in Scotland was closed in a similar incident, amid claims that climate
change is causing a population surge among the species. Scientists
say the number of jellyfish is on the rise due to the increasing acidity of
the world’s oceans driving away the blubbery creatures' natural predators. Ocean
acidification is an often overlooked side effect of burning fossil fuel. Studies
have shown that higher levels of CO2 in the atmosphere doesn’t just trigger
climate change but can make the oceans more acidic. Since the start of the
industrial revolution, acidity levels of the oceans have gone up 30%. link
March 2011: New research on ocean's role in trapping CO2. The ocean traps around
30% of the carbon dioxide emitted into the atmosphere through human activity
and represents, with the terrestrial biosphere, the main carbon sink. The ocean traps
carbon through two principal mechanisms: a biological pump and a physical pump
linked to oceanic currents. Researchers have managed to quantify the role of
these two pumps in an area of the North Atlantic. Contrary to expectations, the
physical pump in this region could be nearly 100 times more powerful on average
than the biological pump. By pulling down masses of water cooled and enriched with
carbon, ocean circulation thus plays a crucial role in deep carbon
sequestration in the North Atlantic. linkJanuary 2011:Amount of carbon absorbed by ecosystem grossly overstated. According to a
new paper published in Science, current carbon accounting methods significantly
overstate the amount of carbon that can be absorbed by forests, plains, and
other terrestrial ecosystems. That is because most current carbon accounting
methods do not consider the methane and carbon dioxide released naturally by
rivers, streams, and lakes. link May 2010: Two UN bodies find massive loss of biodiversity threatened ecosystems. Unless "radical and creative action" is taken quickly to conserve the variety of
life on Earth, natural systems that support lives and livelihoods are at risk of
collapsing, finds a new biodiversity report released today by two United Nations
environmental bodies. The Global Biodiversity Outlook 3 warns that massive further loss of
biodiversity is becoming increasingly likely, and with it, the loss of many
essential services to human societies as several "tipping points" are
approached, in which ecosystems shift to less productive states from which it
may be difficult or impossible to recover. link | Peat:
There is more carbon locked away in the world's peat bogs than in all
the trees put together, and is responsible for 7% of the world's global
emissions from fossil fuels. Yet peat is not recognised by the IPCC
(Intergovernmental Panel on Climate Change) as a being a fossil fuel.
Current fires in Russia indicate the serious threat if peat is ignored
- link |
May 2010: Soils contain two thirds of the world’s terrestrial carbon reserves, far
more than the forests which sit atop the soils, and their accelerating
degradation is releasing CO2 into the atmosphere in a process that could spiral
out of control. Scientists call this process desertification. The soils in Bolivia
provide a stark case of this advancing problem: almost half the soil in the
nation is being affected. The soils in Bolivia provide a stark case of this advancing
problem: almost half the soil in the nation is being affected. The
Bolivian Science and Technology Ministry recently announced that
“desertification… affects 41% of the national territory, 439,432 square
kilometers, where 77% of the population lives, some 6.4 million
people.” Over 89% of them are poor, following a well-established
pattern in which environmental degradation damages those least able to
adapt to it. Many of the factors that have made the Bolivian soil
desertify, such as deforestation, changes in rain patterns, or a
general lack of water, are indirectly or directly related to climate
change. Desertification occurs as a land-mass dries up, the vegetation
on top the soil withers away, the microbes in the soil die, the
resulting soil erodes, and its carbon migrates into the atmosphere in
the form of CO2. link
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