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

Annual Planetary Temperature Continues to Rise

August 17, 2020 / activist360 / Leave a comment

More than 500 scientists from 61 countries have again measured the annual planetary temperature. The diagnosis is not good.

*Wildfire strikes Bandipur national park, one of India’s prime tiger reserves. Image: By NaveenNkadalaveni, via Wikimedia Commons*

August 17, 2020 by Tim Radford, Climate News Network (CC BY-ND 4.0)

LONDON, 17 August, 2020 – Despite global promises to act on climate change, the Earth continues to warm. The annual planetary temperature confirms that the last 10 years were on average 0.2°C warmer than the first 10 years of this century. And each decade since 1980 has been warmer than the decade that preceded it.

The year 2019 was also one of the three warmest years since formal temperature records began in the 19th century. The only warmer years – in some datasets but not all – were 2016 and 2015. And all the years since 2013 have been warmer than all other years in the last 170.

The link with fossil fuel combustion remains unequivocal: carbon dioxide levels in the atmosphere increased by 2.5 parts per million (ppm) in 2019 alone. These now stand at 409 ppm. The global average for most of human history has hovered around 285 ppm.

Two more greenhouse gases – nitrous oxide and methane, both of them more short-lived – also increased measurably.

This millennium has been warmer than any comparable period since the Industrial Revolution.”
—Robert Dunn, of the UK Met Office

The study, in the Bulletin of the American Meteorological Society, is a sobering chronicle of the impact of climate change in the decade 2010-2019 and the year 2019 itself. It is the 30th such report, it is signed by 528 experts from 61 countries, and it is a catalogue of unwelcome records achieved and uncomfortable extremes surpassed.

July 2019 was the hottest month on record. Record high temperatures were measured in more than a dozen nations across Africa, Europe, Asia and the Caribbean. In North America, Alaska scored its hottest year on record.

The Arctic as a whole was warmer than in any year except 2016. Australia achieved a new nationally average daily temperature high of 41.9°C on 18 December, breaking the previous 2013 record by 1.6°C. But even Belgium and the Netherlands saw temperatures higher than 40°C.

For the 32nd consecutive year, the world’s alpine glaciers continued to get smaller and retreat further uphill. For the first time on record in inland Alaska, when measured at 26 sites, the active layer of permafrost failed to freeze completely. In September, sea ice around the Arctic reached a minimum that tied for the second lowest in the 41 years of satellite records.

Catalogue of Extremes

Global sea levels set a new high for the eighth consecutive year and are now 87.6mm higher than the 1993 average, when satellite records began. At a depth of 700 metres, ocean temperatures reached new records, and the sea surface temperatures on average were the highest since 2016.

Drought conditions led to catastrophic wildfires in Australia, in Indonesia, Siberia and in the southern Amazon forests of Bolivia, Brazil and Peru. And around the equator, meteorologists catalogued 96 named tropical storms: the average for 1981 to 2010 was 82. In the North Atlantic, just one storm, Hurricane Dorian, killed 70 people and caused $3.4bn (£2.6bn) in damage in the Bahamas.

“This millennium has been warmer than any comparable period since the Industrial Revolution. A number of extreme events, such as wildfires, heatwaves and droughts, have at least part of their root linked to the rise in global temperature,” said Robert Dunn, of the UK Met Office, one of the contributors.

“And of course the rise in global temperature is linked to another climate indicator, the ongoing rise in emissions in greenhouse gases, notably carbon dioxide, nitrous oxide and methane.” – Climate News Network

Shrublands―Biomes, By GeoDivide

June 29, 2020 / activist360 / Leave a comment

Biomes is a documentary series created by GeoDivide, which explores our planet with beautiful high-quality documentaries including the latest in timelapse and drone technology.

Shrublands are relatively arid regions of Earth where it is too dry for trees to flourish. Often overlooked, they take second or third place to forests or grasslands when it comes to beauty contests. They are a mix of shrubs and grasses, spanning the subtropics to the temperate latitudes. Shrublands have surprising biodiversity considering their parched appearance. They are a place of heat and drought, yet still abundant with life.

From the Mediterranean to Southern California, Central Chile, the Cape of South Africa, and Australia, the Mediterranean scrub biome dominates. While in the subtropics, from Texas and Mexico to the Caatinga of NE Brazil, the Gran Chaco of Paraguay, the Sahel of Africa, these are transitions between the Savannah and deserts.