Atmospheric
Oxygen Decline threatens Humanity’s Existence
Study:
There has been a clear decline in the volume of oxygen in Earth’s
atmosphere over the past 20 years. A recently proposed model predicts
a non-linear decay, which would result in an increasingly rapid
fall-off in atmospheric oxygen concentration, with potentially
devastating consequences for human health.
We predict that humans may
continue to survive in an unprotected atmosphere for ~3600 years.
The
human physiological impact of global
deoxygenation
Global
Cloud Coverage Shifting in Ominous Sign of Climate Change
We didn’t
know enough about clouds until now. What a new study reveals is bad
news.
Bloomberg, 12 July, 2016 When politicians talk
of climate “uncertainty,” they're often casting doubt on
things that are well understood: Warming is happening, and humans are
responsible. When scientists talk about
climate uncertainty, they're usually talking about the clouds. Clouds are tricky because
they do two things at once. All that puffy whiteness blocks solar
energy from reaching the ground, bouncing it back to space, which
provides a net cooling effect. But clouds also act like a blanket,
capping and trapping heat in the lower troposphere, which is where
people who aren't on the International Space Station live. That
ambiguity makes it difficult to simulate with desirable
precision how much and how fast the planet is warming, leaving a
big mystery floating lazily over our heads. Some of that uncertainty
was lifted Monday, and the news isn't good. A new
study in Nature analyzes
almost 30 years of weather observations to show that clouds and
cloudiness are changing in the way scientists would expect in a
warming world. Continental storm tracks—think jet stream—are
shifting poleward, leaving populous subtropical latitudes uncovered.
And the clouds that are forming more often aren't the
low-lying, reflective ones that cool the planet—they're the
huge cottony anvils that rise high in the sky, trapping more heat. "Cloud changes most
consistently predicted by global climate models are currently
occurring in nature," the authors write. "As cloud
tops rise, their greenhouse effect becomes stronger." Also, as the poleward
shift continues, heat from the tropics expands further away from the
equator, an unsettling development for already arid cities in places
like the U.S. southwest. Less light is reflected away from the hot
middle of the Earth, and increased cloud cover toward the poles
creates a thickening blanket that warms the world.
This
graphic shows where the majority of climate models and the majority
of satellite records agree on how cloudiness changed from the 1980s
to the 2000s.
SOURCE: Norris et al;
Nature A couple of things make
clouds such a conundrum to climate scientists. They form through
processes too small to observe, and their layering blocks satellite
views of lower clouds and ground views of higher clouds. Satellite
coverage goes back only to the late 1970s, with technologies designed
for weather monitoring. The new study corrects the weather record to
make sense for climate analysis. “We don’t have a
climate monitoring system,” said Joel Norris, a climatologist at
Scripps Institution of Oceanography and the lead author of the new
paper. “It’s hard to sustain a long-term climate monitoring
program.” Political priorities change, budgets drop, technology
evolves, and climate scientists are left having to extract
consistent, long-term data from measurements taken without the long
term in mind. The corrected data should
help improve their confidence in cloud studies, which currently isn’t
very high. The 2013 science overview put out by the authoritative
Intergovernmental Panel on Climate Change concluded that although
independent sets of cloud observations are similar, “substantial
ambiguity and therefore low confidence [remain] in the observations
of global-scale cloud variability and trends.” “This is an exciting and
comprehensive study,” said Kate Marvel, a scientist at NASA’s
Goddard Institute for Space Studies. “But other studies have found
that these things are happening, and this work provides more evidence
of these effects.” Next up for the study's
authors is to untangle further how natural events, such as volcanoes,
and greenhouse-led warming contribute to the cloud changes.
Ultimately, greater understanding of how clouds behave will help
strengthen projections of the rate and trajectory of global warming.
A
new study from scientists at the University of Miami Rosenstiel
School of Marine and Atmospheric Science and colleagues confirms
rising levels of water vapor in the upper troposphere -- a key
amplifier of global warming -- will intensify climate change impacts
over the next decades. The new study is the first to show that
increased water vapor concentrations in the atmosphere are a direct
result of human activities.
For
every 1 degree C we increase the temperature on the planet we see 7%
more moisture in the atmosphere. We are heading to and beyond
the IPCC worst
case scenario of 6C minimum which will generate another 40% of
moisture in the air. This will lead to a greater number of flooding
events and increased number of lightning strikes and Tornadoes.
This
is an enormous amount of energy and associated warming as water
vapour is in itself a green house gas.
“The
impact of climate change may be worse than previously thought, a new
study suggests”: “As
world leaders hold climate talks in Paris, research shows that land
surface temperatures may rise by an average of almost 8C by 2100, if
significant efforts are not made to counteract climate change.”
Personally
I disagree with the suggestion that it will take until the magic 2100
for our locked in 8C temperature rise. Factor in the myriad of
feedback loops and we could be there in a few decades,not that humans
will survive that long to bare witness.
“The
amount of water vapor in the atmosphere exists in direct
relation to the temperature. If you increase the temperature, more
water evaporates and becomes vapor, and vice versa. So when something
else causes a temperature increase (such as extra CO2 from
fossil fuels), more water evaporates. Then, since water vapor is
a green house gas, this additional water vapor causes the
temperature to go up even further—a positive feedback.”
How
much does water vapor amplify CO2 warming? Studies show
that water vapor feed backroughly doubles the amount of warming
caused by CO2. So if there is a 1°C change caused byCO2, the
water vapor will cause the temperature to go up another 1°C. When
other feedbackloops are included, the total
warming from a potential 1°C change caused by CO2 is, in
reality, as much as 3°C.
“A
warmer atmosphere can hold more moisture, and globally water vapour
increases by 7% for every degree centigrade of warming.”
Human-caused
global warming is causing the upper troposphere to become wetter
We
have long suspected that greenhouse gases which cause the Earth to
warm would lead to a wetter atmosphere. The latest research published
by Eul-Seok Chung, Brian Soden, and colleagues provides new insight
into what was thought to be an old problem. In doing so, they
experimentally verified what climate models have been predicting. The
models got it right… again.
To
be clear, this paper does not prove that water vapor is a greenhouse
gas. We have known that for years. Nevertheless, the paper make a
very nice contribution. The authors show that the long-term increase
in water vapor in the upper troposphere cannot have resulted from
natural causes – it is clearly human caused. This conclusion is
stated in the abstract,
Our
analysis demonstrates that the upper-tropospheric moistening observed
over the period 1979–2005 cannot be explained by natural causes and
results principally from an anthropogenic warming of the climate. By
attributing the observed increase directly to human activities, this
study verifies the presence of the largest known feedback mechanism
for amplifying anthropogenic climate change.
As
stated earlier, climate models have predicted this moistening –
before observations were available. In fact, the models predicted
that the upper troposphere would moisten more than the lower
atmospheric layers. As the authors state,
Given
the importance of upper-tropospheric water vapor, a direct
verification of its feedback is critical to establishing the
credibility of model projections of anthropogenic climate change.
To
complete the experiments, the authors used satellite measurements of
radiant heat. The emissions have changed but it wasn’t clear why
they have changed. Changes could be caused by increases in
temperature or from increased water vapor. To separate the potential
effects, the authors compared the first set of experiments with
others made at a different wavelength. That comparison provided a
direct measure of the separate effect of moistening.
Next,
the authors used the world’s best climate models to test whether
the observed trends could be caused by natural changes in the Earth’s
climate or whether they require a human influence. Sure enough, only
the calculations that included human-emitted greenhouse gases matched
the observations. The authors conclude that,
Concerning
the satellite-derived moistening trend in recent decades, the
relations of trend and associated range among three experiments lead
to the conclusion that an increase in anthropogenic greenhouse gases
is the main cause of increased moistening in the upper troposphere.
The
authors then went further by showing that their computed results
encompass third-party measurements only when the impacts of
human-emitted greenhouse gases are included.
I
chuckled when I asked Dr. Andrew Dessler about this study, and he
told me,
Because
of water vapor’s importance as a greenhouse gas, the water vapor
feedback occupies a central role in the climate system. Over the
years, our understanding of this process has increased steadily, and
this paper is a very useful contribution. It nicely demonstrates that
the observations of upper tropospheric moistening are unlikely to
have arisen without the increase in carbon dioxide from human
activities. At this point, I think it would be fair to say, “stick
a fork in it, the water vapor feedback’s done.”
So
once again, observations have confirmed the models and the scientists
can check another item off their “to do” box.
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