States (Xinhua) -- Scientists have
proposed a new way to tackle climate change by spraying
sun-dimming chemicals into the Earth’s atmosphere, according to
a study published Friday.
Scientists at Harvard and
Yale universities have proposed using a technique known as
Stratospheric Aerosol Injection (SAI), which they believe could
cut the rate of global warming by half, according to a paper
published in the journal Environmental Research Letters.
The technique would involve spraying large amounts of sulfate
particles into the Earth’s lower stratosphere at altitudes as
high as 12 miles (19.3 km).
However, no existing aircraft design—even with extensive
modifications—can reasonably fulfill this mission, said the
The scientists propose developing a new purpose-built
high-altitude tanker with substantial payload capabilities to
deliver the sulfates.
The estimated cost of deploying material is about 2.25
billion U.S. dollars a year over 15 years, according to the
Scientists calculate the number of flights at 4,000 for the
first year, linearly increasing by 4,000 a year.
The report also acknowledges that the technique is purely
"We make no judgment about the desirability of SAI.
"We simply show that a hypothetical deployment program
commencing 15 years hence, while both highly uncertain and
ambitious, would indeed be technically possible from an
"It would also be remarkably inexpensive," the paper said.
Arctic sea ice grows
faster in winter, but not enough to reverse melting trend
WASHINGTON United States (Xinhua) --
Findings of a study by the United States
space agency NASA might be a silver lining: wintertime increases
of Arctic sea ice may have partially slowed down the sea ice
The study released on Thursday has shown that the Arctic sea
ice is thickening at a faster rate during winter although it is
vanishing quicker than it has ever been observed since 1958.
However, this is not an antidote.
The ice cover is not recovering. Only its demise delayed,
according to the study.
The Arctic sea ice cover has lost on average around
two-thirds of its thickness since 1958 and now 70 percent of the
sea ice cap is made of seasonal ice, or ice that forms and melts
within a single year, according to NASA.
"This increase in the amount of sea ice growing in winter
doesn’ t overcome the large increase in melting we’ve observed
in recent decades," said Alek Petty, a sea ice scientist at
NASA’s Goddard Space Flight Center and lead author of the study.
"Our findings highlight some resilience of the Arctic sea ice
cover," Petty said.
"If we didn’t have this negative feedback, the ice would be
declining even faster than it currently is."
The strong ice thickening in winter is not all good news, the
As ice forms at the ocean surface, it releases a lot of
salty, dense water, increasing the mixing of water in the upper
ocean. It will mitigate the strong freshening of the Arctic
Ocean’s surface waters and alter the seasonal balance and the
salinity distribution of the upper ocean.
"Local micro-organisms and ecosystems have to adapt to these
rapidly evolving conditions," said Petty.
The researchers predicted that by the middle of this century,
the further increases in atmospheric and oceanic temperatures
will outweigh the mechanism that allows ice to regrow faster.
When the sea ice is less than 49 centimeters thick at the
beginning of winter, the switch will happen, according to Petty.
Greenhouse gas hits new
record high, will bring more extreme weather: WMO
GENEVA (Xinhua) --
Heat-trapping greenhouse gases in the atmosphere
have reached another new record high, which, with no sign of a
reversal trend, is likely to drive long-term climate change, sea
level rise and more extreme weather, the World Meteorological
Organization (WMO) warned on Thursday.
According to its latest report released on Thursday, the WMO
Greenhouse Gas Bulletin, the global averaged concentrations of
carbon dioxide (CO2) reached 405.5 parts per million (ppm) in
2017, up from 403.3 ppm in 2016 and 400.1 ppm in 2015.
Concentrations of methane and nitrous oxide also rose, while
there was a resurgence of a potent greenhouse gas and ozone
depleting substance called CFC-11, which is regulated under an
international agreement to protect the ozone layer.
Since 1990, there has been a 41 percent increase in total
radiative forcing, which has the warming effect on the climate,
by long-lived greenhouse gases, and CO2 accounts for about 82
percent of the increase in radiative forcing, the report says.
"The last time the Earth experienced a comparable
concentration of CO2 was 3 to 5 million years ago, when the
temperature was two to three degrees Celsius warmer and sea
level was 10 to 20 meters higher than now," said WMO
Secretary-General Petteri Taalas.
"The science is clear. Without rapid cuts in CO2 and other
greenhouse gases, climate change will have increasingly
destructive and irreversible impacts on life on Earth.
The window of opportunity for action is almost closed," he
According to the Intergovernmental Panel on Climate Change (IPCC),
net emissions of CO2 must reach zero around 2050 in order to
keep temperature increases to below 1.5 degrees Celsius.
That means the amount of CO2 entering the atmosphere must
equal the amount that is removed by sinks, natural and
The 1.5-degree target shows that "deep and rapid reductions
of emissions of carbon dioxide and other greenhouse gases will
be needed in all sectors of society and the economy," said IPCC
Chair Hoesung Lee.
Due to the emergency needed, the WMO has initiated the
development of observational based tools that can guide the
emissions reduction actions and confirm their results, for
instance in the oil and gas sector.
A new Integrated Global Greenhouse Gas Information System
(IG3IS) will provide the framework for the development and
standardization of the observational based tools, the WMO said.
Such a system, implemented by countries on a voluntary basis,
will feed into the national emission reporting mechanism to the
UN Framework on Climate Change and the annual Conference of the
South African research
ship departs for Antarctica to study climate change
CAPE TOWN South Africa (Xinhua) --
A South African research ship, the SA Agulhas
II, departed Cape Town for the Antarctica on Thursday,
undertaking a historic anti-climate change expedition.
The mission entails a program of marine and glaciological
research in the Antarctica through the use of highly
sophisticated state of the art technology, and with the SA
Agulhas II as a base.
The expedition team will collect long-term data such as sea
surface temperature, oxygen and carbon measurements, which is
instrumental to further enhance understanding of present day
global climate change, for fundamental research in a number of
areas, said Minister of Environmental Affairs Nomvula Mokonyane
who bid farewell to the team.
"For example, South African and international weather
forecasts rely heavily on the availability of data inputs from
this region and having this continuous data set will enable
better prediction of severe weather phenomena in the context of
global climate change," Mokonyane said.
During this voyage, the SA Agulhas II will also play a
starring role in the historic, international multi-disciplinary
Weddell Sea Expedition, the most important non-governmental
scientific expedition for two decades.
The expedition, which will take place in January and February
2019, comprises world-leading glaciologists, marine biologists,
oceanographers and marine archaeologists who will venture into
remote regions of the Weddell Sea and uncover vital new
scientific data to improve understanding of the area, using that
knowledge to contribute towards the protection of the region.
Research will be focused on the Larsen C Ice Shelf to provide
valuable new insights into the local ecosystem, documenting the
rich and little-studied marine environment, surveying the
seafloor and under the ice and documenting the little-studied
biological systems that lie beneath the ice shelf.
"In addition, the expedition will undertake research to help
us better understand the oceanography and sea ice conditions of
the Weddell Sea and the implications for climate change and
global ocean currents," Mokonyane said.
South African scientists and research entities, working
alongside their international peers, will play a key role in the
Weddell Sea Expedition, she said.
"We hope the Weddell Sea Expedition will inspire more of our
young scientists about Antarctica, its importance to our young
democracy and South Africa’s presence there," the minister said.
South Africa is one of the original 12 signatories of the
Antarctic Treaty of 1959 which regulates international relations
with respect to Antarctica, the Earth’s only continent without a
native human population.
The first South African National Antarctic Expedition was
undertaken in 1959.
The expedition established a permanent presence for South
Africa in Antarctica that still exists to date.
Global warming is a long-term rise in the
average temperature of the Earth’s climate system
Mainstream controversy features public debate over whether
global warming is occurring
Study reconciles dispute about how fast global warming will
happen -- Guardian newspaper
Report has warned climate change could bring widespread
hardship to the United States
Did You Know the Greatest Two-Year Global Cooling Event Just
Don’t Tell Anyone, But We Just Had Two Years Of
Record-Breaking Global Cooling
Despite What You’ve Heard, Global Warming Isn’t Making
Weather More Extreme