Water Discovered For First Time On Potentially Habitable Planet

A handout artist’s impression released on September 11, 2019, by ESA/Hubble shows the K2-18b super-Earth, the only super-Earth exoplanet known to host both water and temperatures that could support life.  M. KORNMESSER / ESA/Hubble / AFP

 

Water has been discovered for the first time in the atmosphere of an exoplanet with Earth-like temperatures that could support life as we know it, scientists revealed Wednesday.

Eight times the mass of Earth and twice as big, K2-18b orbits in its star’s “habitable zone” at a distance — neither too far nor too close — where water can exist in liquid form, they reported in the journal Nature Astronomy.

“This planet is the best candidate we have outside our solar system” in the search for signs of life, co-author Giovanna Tinetti, an astronomer at University College London, told AFP.

“We cannot assume that it has oceans on the surface but it is a real possibility.”

Of the more than 4,000 exoplanets detected to date, this is the first known to combine a rocky surface and an atmosphere with water.

Most exoplanets with atmospheres are giant balls of gas, and the handful of rocky planets for which data is available seem to have no atmosphere at all.

Even if they did, most Earth-like planets are too far from their stars to have liquid water or so close that any H2O has evaporated.

Discovered in 2015, K2-18b is one of hundreds of so-called “super-Earths” — planets with less than ten times the mass of ours — spotted by NASA’s Kepler spacecraft.

Future space missions are expected to detect hundreds more in the coming decades.

 ‘Is Earth unique?’ 

“Finding water in a potentially habitable world other than Earth is incredibly exciting,” said lead-author Angelos Tsiaras, also from UCL.

“K2-18b is not ‘Earth 2.0’,” he said. “However, it brings us closer to answering the fundamental question: is the Earth unique?”

Working with spectroscopic data captured in 2016 and 2017 by the Hubble Space Telescope, Tsiaras and his team used open-source algorithms to analyse the starlight filtered through K2-18b’s atmosphere.

They found the unmistakable signature of water vapour. Exactly how much remains uncertain, but computer modelling suggested concentrations between 0.1 and 50 percent.

By comparison, the percentage of water vapour in Earth’s atmosphere varies between 0.2 percent above the poles, and up to four percent in the tropics.

There was also evidence of hydrogen and helium as well. Nitrogen and methane may also be present but with current technology remain undetectable, the study said.

Further research will be able to determine the extent of cloud coverage and the percentage of water in the atmosphere.

First of many 

Water is crucial in the search for life, in part because it carries oxygen.

“Life as we know is based on water,” said Tinetti.

K2-18b orbits a red dwarf star about 110 light years distant — a million billion kilometres — in the Leo constellation of the Milky Way, and is probably bombarded by more destructive radiation than Earth.

“It is likely that this is the first of many discoveries of potentially habitable planets,” said UCL astronomer Ingo Waldmann, also a co-author.

“This is not only because super-Earths like K2-18b are the most common planets in our galaxy, but also because red dwarfs — stars smaller than our Sun — are the most common stars.”

The new generation of space-based star gazing instruments led by the James Webb Space Telescope and the European Space Agency’s ARIEL mission will be able to describe exoplanet atmospheres in far greater detail.

ARIEL, slated for a 2028 launch, will canvas some 1,000 planets, a large enough sampling to look for patterns and identify outliers.

“Over 4,000 exoplanets have been detected but we don’t know much about their composition and nature,” said Tinetti. “By observing a large sample of planets, we hope to reveal secrets about their chemistry, formation and evolution.”

AFP

Human Diet Causing ‘Catastrophic’ Damage To Planet,’ Study Reveals

In this file photo taken on February 23, 2017, the Jaraua river flows through the Mamiraua Sustainable Development Reserve in Amazonas State, Brazil. PHOTO: Mauro Pimentel / AFP

 

The way humanity produces and eats food must radically change to avoid millions of deaths and “catastrophic” damage to the planet, according to a landmark study published on Thursday.

The key to both goals is a dramatic shift in the global diet — roughly half as much sugar and red meat, and twice as many vegetables, fruits and nuts, a consortium of three dozen researchers concluded in The Lancet, a medical journal.

“We are in a catastrophic situation,” co-author Tim Lang, a professor at the University of London and policy lead for the EAT-Lancet Commission that compiled the 50-page study, told AFP.

Currently, nearly a billion people are hungry and another two billion are eating too much of the wrong foods, causing epidemics of obesity, heart disease, and diabetes.

Unhealthy diets account for up to 11 million avoidable premature deaths every year, according to the most recent Global Disease Burden report.

At the same time the global food system is the single largest emitter of greenhouse gases, the biggest driver of biodiversity loss and the main cause of deadly algae blooms along coasts and inland waterways.

Agriculture — which has transformed nearly half the planet’s land surface — also uses up about 70 percent of the global fresh water supply.

“To have any chance of feeding 10 billion people in 2050 within planetary boundaries” — the limits on Earth’s capacity to absorb human activity — “we must adopt a healthy diet, slash food waste, and invest in technologies that reduce environmental impacts,” said co-author Johan Rockstrom, director of the Potsdam Institute for Climate Change Impact Research.

Where’s the beef?

“It is doable but it will take nothing less than global agricultural revolution,” he told AFP.

The cornerstone of “the great food transformation” called for in the study is a template human diet of about 2500 calories per day.

“We are not saying everyone has to eat in the same way,” Lang said by phone. “But broadly — especially in the rich world — it means a reduction of meat and dairy, and a major increase in plant consumption.”

The diet allows for about seven grammes (a quarter of an ounce) of red meat per day, and up to 14. A typical hamburger patty, by comparison, is 125 to 150 grammes.

For most rich nations, and many emerging ones such as China and Brazil, this would represent a drastic five-to-ten-fold reduction.

Beef is the main culprit.

Not only do cattle pass massive quantities of planet-warming methane, huge swathes of carbon-absorbing forests –- mostly in Brazil -– are cut down every year to make room for them.

“For climate, we know that coal is the low-hanging fruit, the dirtiest of fossil fuels,” said Rockstrom. “On the food side, the equivalent is grain-fed beef.”

It takes at least five kilos of grain to produce a kilo of meat.

And once that steak or lamb chop hits the plate, about 30 percent will wind up in the garbage bin.

Dairy is also limited to about one cup (250 grammes) of whole milk — or its equivalent in cheese or yoghurt — per day, and only one or two eggs per week.

Push back

At the same time, the diet calls for a more than 100 percent increase in legumes such as peas and lentils, along with vegetables, fruits, and nuts.

Grains are considered to be less healthy sources of nutrients.

“We can no longer feed our population a healthy diet while balancing planetary resources,” said The Lancet editor-in-chief Richard Horton.

“For the first time in 200,000 years of human history, we are severely out of sync with the planet and Nature.”

The report drew heavy fire from the livestock and dairy industry, and some experts.

“It goes to the extreme to create maximum attention, but we must be more responsible when making a serious dietary recommendation,” said Alexander Anton, secretary general of the European Dairy Association, noting that dairy products are “packed” with nutrients and vitamins.

Christopher Snowdon of the Institute of Economic Affairs in London said the report “reveals the full agenda of nanny-state campaigners.”

“We expected these attacks,” said Lang. But the same food companies pushing back against these findings realise that they may not have a future if they don’t adapt”, he said.

“The question is: does this come by crisis, or do we start planning for it now.”

Some multinationals responded positively, if cautiously, to the study.

“We need governments to help accelerate the change by aligning national dietary guidelines with healthy and sustainable requirements, and repurposing agricultural subsidies,” the World Business Council for Sustainable Development said in a statement.

AFP

Offsetting Trump, Macron Moves To ‘Make Our Planet Great Again’

 

French Minister for the Ecological and Inclusive Transition Nicolas Hulot addresses Climate Finance Day at The Economy Ministry in Paris on December 11, 2017, on the eve of The Climate World Summit. ERIC PIERMONT / AFP

Moving to fill a climate science gap in Donald Trump’s America, French President Emmanuel Macron named 13 US researchers Monday to be hosted and sponsored by France to help “Make Our Planet Great Again”.

They were among 18 beneficiaries of a Macron-led initiative to boost climate change research in the face of Trump’s rejection of the Paris Agreement to limit climate change.

“I do want to thank you for being here, for your answer to this first call, your decision to move and come to Paris,” the French leader told the chosen few at an event dubbed: “Tech for Planet” held on the eve of his “One Planet Summit”.

“One of our main perspectives is obviously to address the current challenges of climate change,” he said, but also “to boost your research, to boost your initiatives, and to be sure that here you have help in order to deliver more rapidly and to do more.”

Macron has earmarked 30 million euros ($35 million) for his “Make our Planet Great Again” initiative — a play on Donald Trump’s “Make America Great Again” campaign slogan.

Macron made the offer after Trump, who has dismissed climate change as a “hoax”, announced in June the United States would withdraw from the Paris pact, painstakingly negotiated by nearly 200 nations over more than two decades.

The US is the only country to reject the agreement.

Furthermore, Trump has asked Congress to slash the climate research budgets of federal agencies, threatening billions of dollars and thousands of jobs.

Macron’s 30-million-euro pledge has since been matched by French universities and institutions, enough to pay for five-year postings for 50 scientists. More beneficiaries will be chosen later.

Junior researchers will be alloted up to one million euros over four years, covering their salaries, two doctoral students, and expenses.

Senior researchers will each have a 1.5-million-euro budget that provides for two assistants and two students. Spouses will be given French work permits.

$100 billion

“Make Our Planet Great Again is an unexpected opportunity,” Alessandra Giannini, a researcher at The Earth Institute at Columbia University, one of the 18 recipients, told AFP.

For fellow beneficiary Nuria Teixido of Stanford University, the initiative was an important recognition “that science plays an important role” in confronting the problem of climate change.

Tuesday’s summit will gather leaders including UN chief Antonio Guterres, Mexico’s Enrique Pena Nieto, Theresa May of Britain, Spain’s Mariano Rajoy, and European Commission President Jean-Claude Juncker to talk about climate finance.

It follows just weeks after the 23rd annual Conference of Parties to the UN Climate Convention, which was held in Bonn.

The US president’s rejection of the Paris pact threw a long shadow over the talks in Germany, where officials from Washington defended the use of fossil fuels blamed for global warming.

Trump was not invited to the latest talks, and Washington will be represented by an embassy official.

The gathering will look at sources of finance, public and private, to help countries make the costly shift to cleaner energy sources and to raise their defences against climate change impacts such as sea-level rise, harsher droughts, floods and superstorms, and disease spread.

Rich nations have pledged to muster $100 billion in climate finance for developing nations per year from 2020.

On 2015 trends, total public financing would reach about $67 billion by that date, according to a report of the Organisation for Economic Cooperation and Development (OECD).

Trump has said the United States — which had pledged $3 billion towards the Green Climate Fund, of which it delivered $1 billion under Barack Obama — would not fulfil its climate finance commitments.

On Monday, UN climate chief Patricia Espinosa said “a practical path forward for finance is needed” if climate change is to be braked.

Political agreements “will not be enough if we do not update and reset the global finance architecture and make all developement low-emission, resilient and sustainable,” she said.

AFP