What the scientists are saying…
The world’s trees in danger
A third of the world’s 58,497 tree species are facing extinction, a new report has warned. The five-year study, compiled by 500 experts from 60 institutions, found that 142 species were already extinct, and that 442 were on the brink of extinction, meaning that fewer than 50 examples remained in the wild. These ranged from the Menai whitebeam, which grows in North Wales, to Mulanje cedar in Malawi. The biggest threats were listed as forest clearance for crops (which is affecting 29% of species), logging (27%), livestock grazing (14%) development (13%) and fire (13%). Madagascar and Brazil were the countries with the highest number of at-risk trees. Elsewhere, the report notes that oak trees are being lost to farming and development in parts of Mexico, Chile and Argentina, while in China wild magnolia trees are threatened by unsustainable plant collection. In the UK and the US, trees such as ash are at risk from invasive species and disease. In total, 58% of European species are at risk. The report’s authors describe trees as the “backbone of the natural ecosystem” – and stress that if their decline continues unchecked, it could have catastrophic knock-on consequences. “It’s like a Jenga tower,” said Dr Malin Rivers, of Botanic Gardens Conservation International. “Pull the wrong one out, and the ecosystem falls apart.”
Komodo dragon “endangered”
It has a fearsome reputation, but the Komodo dragon – the world’s largest living lizard – has long been classified as vulnerable, and has now been reclassified as endangered. “It’s had a genuine change in status, a deterioration,” said Craig Hilton-Taylor, of the International Union for Conservation of Nature, which compiles the Red List of Threatened Species. “It’s moving towards extinction.” The carnivorous lizards, which live on a handful of islands in Indonesia, grow up to ten-foot-long. They have serrated teeth, venom-laced saliva, armoured scales – and a remarkably acute sense of smell. Using their forked tongues, they test the air; an organ in the roof of their mouths analyses the information, and alerts them to the presence of warm-blooded animals to a distance of about six miles. Their prey include forest-dwelling pigs, deer, buffalo, and the fruit bats that hang low in the trees. Attacks on humans are not unknown but they are rare: Komodos are shy creatures, and until last year, conservationists didn’t even know where exactly they lived. Now, they are threatened not only by human activity on the islands, but also by rising sea levels: these are predicted to affect at least 30% of their habitat in the next 45 years.
Making toast a healthier option
Scientists are gene-editing wheat to slash levels of a compound that is believed to cause cancer. Asparagine is a naturally occurring amino acid that is found in foods including bread and potatoes. When heated to a high level, it is converted into acrylamide – which is classed as a probable carcinogen for humans. Now, using Crispr gene editing, a British team is creating wheat that has little or no asparagine, so that bread can be toasted with no risk. Scientists argue that gene editing is fundamentally different from conventional genetic modification, because it only involves removing bits of DNA, to eliminate or enhance certain traits – a process that can occur naturally. By contrast GM involves inserting new genetic material, borrowed from other organisms. Under EU law, experiments on the two are nevertheless subject to the same stringent regulations. But Defra has allowed scientists at Rothamsted Research in Hertfordshire to grow the gene-edited wheat for a new trial, signalling a new approach post-Brexit.
The oil must stay in the ground
To hold global warming at 1.5°C above pre-industrial levels, the level set by the Paris Agreement, 60% of the world’s oil and fossil gas reserves, and 90% of its coal, will have to stay in the ground, climate modellers at University College London have found. That would require 97% of the coal in the US and Russia to go unextracted, along with two-thirds of the oil in the Middle East. However, the paper, published in Nature, warns that its figures may well be an underestimate, partly because the model relies on the large-scale deployment of technologies for removing CO2 that are as yet unproven.