‘We Need to Hear These Poor Trees Scream’: Unchecked Global Warming Means Big Trouble for Forests

‘We Need to Hear These Poor Trees Scream’: Unchecked Global Warming Means Big Trouble for Forests

SOURCE: Inside Climate Change DATE: April 25, 2020 SNIP: Tim Brodribb has been measuring all the different ways global warming kills trees for the past 20 years. With a microphone, he says, you can hear them take their last labored breaths. During blistering heat waves and droughts, air bubbles invade their delicate, watery veins, cracking them open with an audible pop. And special cameras can film the moment their drying leaves split open in a lightning bolt pattern, disrupting photosynthesis. “We really need to be able to hear these poor trees scream. These are living things that are suffering. We need to listen to them,” said Brodribb, a plant physiologist at the University of Tasmania who led a recent study that helps identify exactly when, where and how trees succumb to heat and dryness. The study, published April 17 in the journal Science, reviewed the last 10 years of research on tree mortality, concluding that forests are in big trouble if global warming continues at the present pace. Most trees alive today won’t be able to survive in the climate expected in 40 years, Brodribb said. The negative impacts of warming and drying are already outpacing the fertilization benefits of increased carbon dioxide. Trees and forests can be compared with corals and reefs, he said. Both are slow-growing and long-lived systems that can’t easily move or adapt in a short time to rapid warming and both have relatively inflexible damage thresholds. For corals, a global tipping point was reached from 2014 to 2016. In record-warm oceans, reefs around the world bleached and died. The new paper shows that the...
Trees on commercial UK plantations ‘not helping climate crisis’

Trees on commercial UK plantations ‘not helping climate crisis’

SOURCE: The Guardian DATE: March 10, 2020 SNIP: Commercial tree plantations in Britain do not store carbon to help the climate crisis because more than half of the harvested timber is used for less than 15 years and a quarter is burned, according to a new report. While fast-growing non-native conifers can sequester carbon more quickly than slow-growing broadleaved trees, that carbon is released again if the trees are harvested and the wood is burned or used in products with short lifespans, such as packaging, pallets and fencing. Of the UK’s 2018 timber harvest, 23% was used for wood fuel, while 56% was taken to sawmills. Only 33% of the wood used by sawmills was for construction, where wood used in permanent buildings can lock in carbon for decades. Much of sawmill wood was used for fencing (36%) with a service life of 15 years, or packaging and pallets (24%) or paper (4%). “There is no point growing a lot of fast-growing conifers with the logic that they sequester carbon quickly if they then go into a paper mill because all that carbon will be lost to the atmosphere within a few years,” said Thomas Lancaster, head of UK land policy at the Royal Society for the Protection of Birds (RSPB), which commissioned the report. “We should not be justifying non-native forestry on carbon grounds if it’s not being used as a long-term carbon store.” The Committee on Climate Change has called for 1.5 billion new trees by 2050 – requiring planting on 30,000 hectares (74,000 acres) of land a year, increasing Britain’s forest cover from 13% to 19%....
Logging Is the Lead Driver of Carbon Emissions from US Forests

Logging Is the Lead Driver of Carbon Emissions from US Forests

SOURCE: Earth Island Journal and Open Access Research DATE: April 4, 2019 SNIP: Protecting forest ecosystems is critical in the fight to limit global warming — when forests are disturbed they release carbon, but when left to grow they actively pull carbon out of the air and store it. When left standing, forests also provide optimal natural protection against extreme weather events, like flooding and droughts. Many people are aware of the importance of protecting rainforests in Brazil to help mitigate climate change, but few realize that more logging occurs in the US, and more wood is consumed here, than in any other nation globally. The rate and scale of logging in the Southeastern US alone is four times that in South American rainforests. The Trump Administration and industry have been aggressively promoting misinformation about forests and wildland fires, while advocating for large increases in logging under the guises of “forest health,” “fuel reduction,” “renewable energy,” and reducing carbon emissions. But the promotion of logging to supposedly curb carbon emissions is just part of the Administration’s ongoing alignment with industry and troubling pattern of climate science denial. Carbon emissions from logging in the US are ten times higher than the combined emissions from wildland fire and tree mortality from native bark beetles. Fire only consumes a minor percentage of forest carbon, while improving availability of key nutrients and stimulating rapid forest regeneration. Within a decade after fire, more carbon has been pulled out of the atmosphere than was emitted. When trees die from drought and native bark beetles, no carbon is consumed or emitted initially, and carbon emissions from...
Climate change: Warning from ‘Antarctica’s last forests’

Climate change: Warning from ‘Antarctica’s last forests’

SOURCE: BBC DATE: April 3, 2019 SNIP: Scramble across exposed rocks in the middle of Antarctica and it’s possible to find the mummified twigs of shrubs that grew on the continent some three to five million years ago. This plant material isn’t much to look at, but scientists say it should serve as a warning to the world about where climate change could take us if carbon emissions go unchecked. The time period is an epoch geologists call the Pliocene, 2.6-5.3 million years ago. It was marked by temperatures that were significantly warmer than today, perhaps by 2-3 degrees globally. These were conditions that permitted plant growth even in the middle of the White Continent. Higher, too, were sea-levels. It’s uncertain by how much, but possibly in the region of 10-20m above the modern ocean surface. What’s really significant, though, is that the amount of carbon dioxide in the atmosphere was very similar to what it is today – at around 400 CO2 molecules for every million molecules of air. Indeed, the Pliocene was the last time in Earth history that the air carried this same concentration of the greenhouse gas. And it tells you where we’re heading if we don’t get serious about addressing the climate problem. Temperatures may currently be lower than in the Pliocene, but that’s only because there is a lag in the system. Prof Jane Francis, the director of the British Antarctic Survey, pulled her fossilised shrub material from rocks just 500km from the South Pole. “These are twigs similar to southern beech,” she told BBC News. “I like to call them the remnants...
Iconic Forests Reaching Climate Tipping Points in American West

Iconic Forests Reaching Climate Tipping Points in American West

SOURCE: Inside Climate News DATE: March 11, 2019 SNIP: Climate change in the American West may be crossing an ominous threshold, making parts of the region inhospitable for some native pine and fir forests to regrow after wildfires, new research suggests. As temperatures rise, the hotter, drier air and drier soil conditions are increasingly unsuitable for young Douglas firs and ponderosa pines to take root and thrive in some of the region’s low-elevation forests, scientists write in a study published Monday in the Proceedings of the National Academy of Sciences. Wildfires in these areas could lead to abrupt ecosystem changes, from forest to non-forest, that would otherwise take decades to centuries, the study says. “Once a certain threshold was crossed, then the probability of tree establishment decreased rapidly,” said Kimberley Davis, a researcher at the University of Montana and lead author of the study. “The climate conditions are just a lot less suitable for regeneration.” Davis and her colleagues looked at growth rings of nearly 3,000 young trees in 33 fire-damaged areas of California, Colorado, the Northern Rockies and the southwestern United States to see when the forests recovered after fires over the past 30 years. Analyzing climate data over the same period, they found certain thresholds involving summer humidity for ponderosa pine, surface temperature for Douglas fir, and soil moisture for both species, beyond which there was a sharp decline in forest regrowth. The warmer, drier air isn’t harming mature trees, but it is preventing future generations from growing, Davis said. “There could be a lot of areas where there is currently forest but if we have a...