African Desert is Home to Abundant Forest Growth

November 2, 2020 / activist360 / Leave a comment

Researchers have found an unknown wealth of trees in an African desert zone supposedly too arid for green growth.

Rural Burkina Faso: Part of the Sahel, but with plenty of trees. Image: By Adam Jones, Ph.D., via Wikimedia Commons — *Burkina Faso: Part of the Sahel, but with plenty of trees. Image: By Adam Jones, Ph.D., via Wikimedia Commons.*

By Tim Radford, Climate News Network (CC BY-ND 4.0)

With help from high resolution satellite imagery and some advanced artificial intelligence techniques, European scientists have been counting the trees in a parched African desert.

They pored over 1.3 million square kilometres of the waterless western Sahara and the arid lands of the Sahel to the south, to identify what is in effect an unknown forest. This region − a stretch of dunes and dryland larger than Angola, or Peru, or Niger − proved to be home to 1.8 billion trees and shrubs with crowns larger than three square metres.

“We were very surprised to see that quite a few trees actually grow in the Sahara Desert because up till now, most people thought that virtually none existed. We counted hundreds of millions of trees in the desert alone,” said Martin Brandt, a geographer at the University of Copenhagen in Denmark, who led the research.

He and colleagues from Germany, France, Senegal, Belgium and Nasa in the US report in the journal Nature that they used an artificial intelligence technique called “deep learning” and satellite imagery so advanced that − from space − a camera could resolve an object half a metre or more in diameter, to see if they could answer unresolved questions about all those trees beyond the world’s forests.

Trees outside of forested areas are not usually included in climate models, and we know very little about their carbon stocks. They are an unknown component in the global carbon cycle”.
—Martin Brandt, lead researcher, University of Copenhagen

Trees matter, wherever they are. In cities, they enhance urban life and sustain property values. In forests, they conserve and recycle water, shelter millions of animals and smaller plants, and absorb atmospheric carbon. In grasslands they conserve soils, offer habitat for species and provide subsistence fuel, food and fodder for humans and animals.
But trees beyond the forests are an unknown factor when it comes to the puzzle of the global carbon budget and the great challenge of containing runaway climate change.

“Trees outside of forested areas are not usually included in climate models, and we know very little about their carbon stocks,” Dr Brandt said. “They are basically a white spot on maps and an unknown component in the global carbon cycle.”

The total identified in the target zone of the Sahara and the Sahel is almost certainly an under-estimate: the technology did not and could not pinpoint trees with a crown or shade area smaller than 3 square metres.

The study adds to the chronicle of surprises delivered by tree and forest research. In the last few years scientists have essayed a global census of woody growths wider than 5cms at breast height − that’s the botanist’s definition of a tree − and arrived at a total of more than 3 trillion.

New map possible

They have also counted the different kinds of tree: more than 60,000 species. They have already made attempts to measure the extent of tree cover in dryland and savannah regions and identified a kind of hidden forest.

They have calculated that a determined global tree planting campaign could absorb enough carbon to make a formidable difference to the challenge of global heating, and they have confirmed that conserved natural forests are, even on the simple basis of human economics, a bargain: forests are worth more to the world when they flourish than when they are cleared.

The new approach − the match of artificial intelligence with high resolution imagery − could one day help identify not just trees, but different tree species. It could, researchers hope, eventually even provide a reliable count of trees in a forest, although where canopies overlap it will always be difficult to number the trunks that support them. It offers the world’s forest scientists a new starting point for a map of all the planet’s trees.

“Doing so wouldn’t have been possible without this technology,” Dr Brandt said. “Indeed, I think it marks the beginning of a new scientific era.”

Original publication: Climate News Network — LONDON, 27 October, 2020

World Makes Haste Too Slowly on Cutting Energy Use

October 18, 2020 / activist360 / Leave a comment

The annual report card on the global energy industry says progress towards lower energy use must be much faster.

By Kieran Cooke, Climate News Network (CC BY-ND 4.0).

*A rich source of methane: Gas hydrate beneath a rock in the Gulf of Mexico. Image: By US Geological Survey (public domain), via Wikimedia Commons*

The world is dragging its feet on efforts to tackle the climate crisis by reducing its energy use, according to a global watchdog.

In its World Energy Outlook 2020, the lnternational Energy Agency (IEA) says that while emissions of carbon dioxide (CO2, the main climate-changing greenhouse gas), are falling, the reduction needs to be far steeper to make any meaningful impact.

“Despite a record drop in global emissions this year, the world is far from doing enough to put them into decisive decline”, says Fatih Birol, the IEA’s executive director.

The Agency says energy demand is set to drop by 5% in 2020, with an overall decline of 7% in emissions of CO2 from the global energy sector. This means that annual emissions of CO2 are back to where they were a decade ago, the report says.

Oil demand this year is likely to be down by 8%, while coal use will fall by 7%.

Solar projects now offer some of the lowest-cost electricity ever seen.”

That’s the headline good news: the bad news is that emissions of methane – among the most potent of greenhouse gases – are rising, says the report.

Total global investment in the energy sector is also falling dramatically, and is set to be down 18% year on year.

That means that despite the rise of renewable energy, particularly of solar power, governments, utilities and corporations around the world are still not spending enough to bring about a major transition in energy use – and to meet the challenge of catastrophic climate change.

“Only an acceleration in structural changes to the way the world produces and consumes energy can break the emissions trend for good”, says the IEA.

Problem grids

While hydropower is still the leading source of renewable power, solar is described as the new king of electricity.

“With sharp cost reductions over the past decade, solar PV [solar photovoltaic energy] is consistently cheaper than new coal- or gas-fired power plants in most countries, and solar projects now offer some of the lowest-cost electricity ever seen.”

A major problem is that as solar and wind projects are installed and expanded, other parts of the energy sector also need to be developed, particularly infrastructure associated with electricity grids.

In many parts of the world energy utilities are in severe financial straits and have little or no money to maintain or invest in achieving more efficiencies and in infrastructure.

“Electricity grids could prove to be the weak link in the transformation of the power sector, with implications for the reliability and security of electricity supply”, says the IEA.

Covid-19’s effects

The report says it’s not just the energy industry that has to change. “To reach net-zero emissions, governments, energy companies, investors and citizens all need to be on board – and will all have unprecedented contributions to make.”

The Covid crisis is a major factor in assessing the global energy outlook.

The pandemic, says the IEA, has caused more disruption in the energy sector than any other event in recent history, with impacts for years to come.

“It is too soon to say whether today’s crisis represents a setback for efforts to bring about a more secure and sustainable energy system, or a catalyst that accelerates the pace of change”, the report says. —Climate News Network, LONDON, 16 October, 2020

Climate Heat Melts Arctic Snows and Dries Forests

October 13, 2020 / activist360 / Leave a comment

Fires now blaze under Arctic snows, where once even the wettest rainforests burned. Climate change delivers unlikely outcomes.

*Boggy tundra in the western Arctic lets peat layers build up in the soil. Image: By Western Arctic National Parklands, via Wikimedia Commons*

October 12, 2020 by Tim Radford, Climate News Network (CC BY-ND 4.0)

LONDON, 12 October, 2020 − The northern polar region isn’t just warming: it’s also smoking, as the rising heat thaws the Arctic snows. Researchers have identified a new class of fire hazard.

High above the Arctic Circle, fires that flared a year ago continued to smoulder under the snow through the winter to flare up again − two months earlier than usual, and on a scale not seen before.

And if the notion of fire and ice seems a surprise, prepare for the idea of a blazing rainforest. In a second and separate study, researchers exploring the climate lessons from the deep past 90 million years ago have found that, if the atmosphere is rich enough in oxygen, then even the wettest foliage can ignite and burn, to consume perhaps up to 40% of the world’s forest.

Scientists from the US report in Nature Geoscience that they have identified an unexpected threat from “zombie fires” which, despite heavy snowmelt, they say “can smoulder in carbon-rich peat below the surface for months or years, often only detectable through smoke released at the surface, and can even occur through cold winter months.”

The climate change we are causing now, it’s not something where if we don’t fix it, only our grandkids will have to deal with it. The impacts are really long-lasting”
—Garrett Boudinot, then at the University of Boulder Colorado and now with the Colorado Wildlife Council

They warn that in the fast-changing climate of the highest northern latitudes, the evidence from last year and this suggest that extreme temperatures and drier conditions mean there is a lot more surface fuel in the Arctic to catch fire and melt the Arctic snows.

Dwarf shrubs, sedges, mosses and grasses are invading the tundra, to join the surface peat, and even the bogs, fens and marches of the tundra are now burning. In all, 50% of the detected fires above 65° North − many in the Russian Arctic − happened on permafrost: that is, on ever-icy soils.

“It’s not just the amount of burned area that is alarming,” said Merritt Turetsky of the University of Colorado at Boulder, and one of the authors. “There are other trends we noticed in the satellite data that tell us how the Arctic fire regime is changing and what this spells for our climate future.”

Wildfires are on the increase now, in a world in which climate change has delivered hotter and drier conditions for many regions. Unexpectedly, according to a second study in Nature Geoscience, fossilized evidence in rocks in Utah has delivered evidence of massive and sustained forest fires, in the form of polycyclic aromatic hydrocarbons preserved in black shales laid down in the Cretaceous.

Huge absorption rate

Researchers pieced together a story of dramatic climate change 94 million years ago, when carbon dioxide built up in the atmosphere, and land and sea plants began to absorb it from the atmosphere on a massive scale. Microbial respiration stepped up too, and parts of the ocean became increasingly low in oxygen.

During 100,000 years of this, so much carbon had been buried in the ground or the oceans that – with the release of molecular oxygen, the O2 in CO2 − atmospheric oxygen levels began to increase. And with that, the scientists say, so did the probability of forest fires, even in wet forest ecosystems. Altogether, perhaps 30% to 40% of the planet’s forests were consumed by fire over 100 millennia.

“One of the consequences of having more oxygen in the atmosphere is that it’s easier to burn fires. It’s the same reason you blow on embers to stoke a fire,” said Garrett Boudinot, then at the University of Boulder Colorado and now with the Colorado Wildlife Council, who led the research.

“This finding highlights the prolonged impacts of climate change. The climate change we are causing now, it’s not something where if we don’t fix it, only our grandkids will have to deal with it. The history of climate change in Earth history tells us that the impacts are really long-lasting.” − Climate News Network