Feed aggregator
Current emissions could already warm world to dangerous levels: study
Melting ice sheets – such as this one in Greenland – are one way the Earth amplifies global warming. Ice sheet image from www.shutterstock.comCurrent greenhouse gas concentrations could warm the world 3-7℃ (and on average 5℃) over coming millennia. That’s the finding of a paper published in Nature today.
The research, by Carolyn Snyder, reconstructed temperatures over the past 2 million years. By investigating the link between carbon dioxide and temperature in the past, Snyder made new projections for the future.
The Paris climate agreement seeks to limit warming to a “safe” level of well below 2℃ and aim for 1.5℃ by 2100. The new research shows that even if we stop emissions now, we’ll likely surpass this threshold in the long term, with major consequences for the planet.
What is climate sensitivity?How much the planet will warm depends on how temperature responds to greenhouse gas concentrations. This is known as “climate sensitivity”, which is defined as the warming that would eventually result (over centuries to thousands of years) from a doubling of CO₂ concentrations in the atmosphere.
The measure of climate sensitivity used by the Intergovernmental Panel on Climate Change (IPCC) estimates that a doubling of CO₂ will lead to 1.5-4.5℃ warming. A doubling of CO₂ levels from before the Industrial Revolution (280 parts per million) to 560ppm would likely surpass the stability threshold for the Antarctic ice sheet.
As the world warms, it triggers changes in other systems, which in turn cause the world to warm further. These are known as “amplifying feedbacks”. Some are fast, such as changes in water vapour, clouds, aerosols and sea ice.
Others are slower. Melting of the large ice sheets, changes in the distribution of forests, plants and ecosystems, and methane release from soils, tundra or ocean sediments may begin to come into play on time scales of centuries or less.
Other research has shown that during the mid-Pliocene epoch (about 4.5 million years ago) atmospheric CO₂ levels of about 365-415ppm were associated with temperatures about 3–4 °C warmer than before the Industrial Revolution. This suggests that the climate is more sensitive than we thought.
This is concerning because since the 18th century CO₂ levels have risen from around 280ppm to 402ppm in April this year. The levels are currently rising at around 3ppm each year, a rate unprecedented in 55 million years. This could lead to extreme warming over the coming millennia.
More sensitive than we thoughtThe new paper recalculates this sensitivity again – and unfortunately the results aren’t in our favour. The study suggests that stabilisation of today’s CO₂ levels would still result in 3-7℃ warming, whereas doubling of CO₂ will lead to 7-13℃ warming over millennia.
The research uses proxy measurements for temperature (such as oxygen isotopes and magnesium-calcium ratios from plankton) and for CO₂ levels, calculated for every 1,000 years back to 2 million years ago.
Some other major findings include:
The Earth cooled gradually to about 1.2 million years ago, followed by an increase in the size of ice sheets around 0.9 million years ago, and then followed by around 100,000-year-long glacial cycles.
Over the last 800,000 years, and particularly during glacial cycles, atmospheric greenhouse gas concentrations and global temperature were closely linked.
The study shows that for every 1℃ of global average warming, Antarctica warms by 1.6℃.
So what does all this mean for the future?Global warming past and future, triggered initially by either changes in solar radiation or by greenhouse gas emissions, is driven mainly by amplifying feedbacks such as warming oceans, melting ice, drying vegetation in parts of the continents, fires and methane release.
Current CO₂ levels of around 400ppm, combined with methane (rising toward 1,900 parts per billion) and nitric oxide (around 310ppb), are already driving such feedbacks.
According to the new paper, such greenhouse gas levels are committing the Earth to extreme rises of temperature over thousands of years, with consequences consistent with the large mass extinctions.
The IPCC suggests warming will increase steadily as greenhouse gases increase. But the past shows there will likely be abrupt shifts, local reversals and tipping points.
Abrupt freezing events, known as “stadials”, follow peak temperatures in the historical record. These are thought to be related to the Mid-Atlantic Ocean Current. We’re already seeing marked cooling of ocean regions south of Greenland, which may herald collapse of the North Atlantic Current.
As yet we don’t know the details of how different parts of the Earth will respond to increasing greenhouse gases through both long-term warming and short-term regional or local reversals (stadials).
Unless humanity develops methods for drawing down atmospheric CO₂ on a scale required to cool the Earth to below 1.5°C above pre-industrial temperature, at the current rate of CO₂ increase of 3ppm per year we are entering dangerous uncharted climate territory.
Andrew Glikson does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond the academic appointment above.
South Africa: 'Saving endangered species is the responsibility of everyone'
As the 17th world wildlife conference opens, South Africa’s environment minister Edna Bomo Molewa explains the country’s commitment to protecting wildlife
Over the next two weeks, South Africa will welcome an estimated 3,500 delegates to Cop17, the 17th Conference of the Parties to the Convention on the International Trade in Endangered Species of Wild Fauna and Flora (Cites).
Related: Saving Africa's elephants: 'Can you imagine them no longer existing?'
Continue reading...US emissions set to miss 2025 target in Paris climate change deal, research finds
Even if US implements emissions-cutting proposals it could still overshoot target by nearly 1bn tonnes of greenhouse gases, according to scientific study
The US is on course to miss its emissions reduction target agreed in the Paris climate accord nine months ago, with new research finding that the world’s largest historical emitter doesn’t currently have the policies in place to meet its pledge.
Even if the US implements a range of emissions-slashing proposals that have yet to be introduced, the nation could still overshoot its 2025 target by nearly 1bn tonnes of greenhouse gases. This failure would have profound consequences for the US’s position as a climate leader, as well for the global effort to stave off the dangerous heatwaves, sea level rise and extreme weather associated with climate change.
Continue reading...Animal trafficking: the $23bn criminal industry policed by a toothless regulator
Convention on International Trade in Endangered Species finds itself confronting powerful networks, but has no detectives, police powers or firearms
The illegal trade in wildlife is a most attractive crime. But it is highly destructive, and its scale is threatening the extinction of some of the world’s most iconic species.
It is also grotesquely cruel: poachers slice off the faces of live rhinos to steal their horns; militia groups use helicopters to shoot down elephants for their tusks; factory farmers breed captive tigers to marinate their bones for medicinal wine and fry their flesh for the dinner plate; bears are kept for a lifetime in tiny cages to have their gall bladders regularly drained for liver tonic. But for any criminal who wants maximum money for minimum risk, it is most attractive.
SpaceX 'Mars' rocket engine tested
The crime family at the centre of Asia's animal trafficking network
Bach brothers based in Vietnam and Thailand are responsible for smuggling thousands of tonnes of elephant ivory, rhino horn and other endangered species
There is a simple reason why there is always trouble in Nakhon Phanom. It is the reason why the US air force came here during the Vietnam war, and the reason why this dull and dusty town in north-east Thailand now serves as a primary gateway on the global animal trafficking highway. It is all to do with geography.
Nakhon Phanom, population 30,000, sits on the western bank of the Mekong river and is directly opposite the shortest route across Laos, on the other side of the river, and into Vietnam.
Continue reading...Revealed: the criminals making millions from illegal wildlife trafficking
Exclusive: Investigation uncovers the ringleaders profiting from $23bn annual trade in illicit animals after more than a decade of undercover surveillance
- Help fund our journalism by becoming a Guardian supporter.
A major investigation into global wildlife crime today names for the first time key traffickers and links their illegal trade to corrupt officials at the highest levels of one Asian country.
The investigation, published by the Guardian, exposes the central role of international organised crime groups in mutilating and killing tens of thousands of animals and threatening to eliminate endangered species including tigers, elephants and rhinos.
Continue reading...'Colossal' wasp nest found in Corby attic
China's Geely auto group backs Bloodhound
The Madhouse Effect of climate denial | John Abraham
A new book by Mann and Toles explores climate science and denial with clarity and humor
A new book by Michael Mann and Tom Toles takes a fresh look on the effects humans are having on our climate and the additional impacts on our politics. While there have been countless books about climate change over the past two decades, this one – entitled The Madhouse Effect - distinguishes itself by its clear and straightforward science mixed with clever and sometimes comedic presentation.
In approximately 150 pages, this books deals with the basic science and the denial industry, which has lost the battle in the scientific arena and is working feverishly to confuse the public. The authors also cover potential solutions to halt or slow our changing climate. Perhaps most importantly, this book gives individual guidance – what can we do, as individuals, to help the Earth heal from the real and present harm of climate change?
Continue reading...Planes need to stop existing in a parallel universe when it comes to the climate fight
Curbing flight emissions is essential to meeting the Paris pact, but planes are completely absent from the text, face no legal fuel efficiency requirements or limits on CO2 emissions. But all that is about to change
In the coming weeks, the Paris climate agreement could be about to enter into force. Action to meet the deal’s targets of holding global warming to 2C is most clearly visible in the energy sector - where a low-carbon transition is underway. There is, however, one sector where, until now, action has been invisible owing to its exemption from contributing to the fight to limit carbon pollution: international aviation.
Aviation is one of the top-10 global carbon polluters. The industry emits more CO2 each year than the 129 countries with the lowest annual emissions. Worryingly, those emissions are expected to balloon by 300% if no concerted action is taken sooner rather than later. In 2010, 2.4 billion passengers travelled by plane, but by 2050 that number is expected to rise to 16 billion.
The global agreement reached in Paris last December committed the world’s governments to fighting climate change. Curbing aviation emissions is absolutely essential to fulfilling those commitments. However, aviation was conspicuous by its absence from the text.
Getting serious about North Korean nukes
A world without cars: cities go car-free for the day - in pictures
From Bogota to Paris to Istanbul, cities around the world have been imposing traffic restrictions to mark World Car-Free Day. Is it a vision of the future?
Continue reading...Good riddance to rats
Know your NEM: Victoria futures price jumps on talk of Hazelwood
Fracking: No shale gas wells to be drilled in UK this year
Despite strong government support, fracking company Cuadrilla says progress on the ground remains slow, as it awaits a decision on two key sites in Lancashire
No shale gas wells will be drilled in Britain this year, the industry has confirmed, as a key fracking decision nears.
Within the next fortnight, the government will decide whether to accept shale company Cuadrilla’s appeal against Lancashire county council’s decision last year to turn down its application for two fracking sites.
Maralinga nuclear tests, 60 years on: a reminder not to put security before safety | Liz Tynan
Australia stood by while Britain’s military elite trashed tracts of its landscape then left. Menzies had said yes without even consulting his cabinet
It is 27 September 1956. At a dusty site called One Tree, in the northern reaches of the 3,200 sq km Maralinga atomic weapons test range in outback South Australia, the winds have finally died down and the countdown begins.
The site has been on alert for more than two weeks but the weather has constantly interfered with the plans. Finally, Prof Sir William Penney, head of the UK Atomic Weapons Research Establishment, can wait no longer. He gives the final, definitive go-ahead.
Continue reading...Attacks on wind and solar policies turn to state initiatives
An exuberance of life on the undrained fen
Woodwalton Fen, Cambridgeshire Bladderworts and bog myrtle, dragonflies, water fleas and hornets all thrive in the vicinity of a bungalow built for natural historians
A remnant rectangle of wetland, two square kilometres of wildlife that before humans drained the fens was part of a 2,000 square km wet, peaty wilderness. Many species have disappeared, but an exuberance of intertwined life still thrives on this little patch.
Related: In the service of the queen, hornets hunt day and night
Continue reading...GCL E-KwBe sales commence in Australia, taking on the battery storage giants
Pages
