High CO2 levels cause plants to thicken their leaves, could worsen climate change effects

High CO2 levels cause plants to thicken their leaves, could worsen climate change effects

SOURCE: Phys.org DATE: October 1, 2018 SNIP: Plant scientists have observed that when levels of carbon dioxide in the atmosphere rise, most plants do something unusual: They thicken their leaves. And since human activity is raising atmospheric carbon dioxide levels, thick-leafed plants appear to be in our future. But the consequences of this physiological response go far beyond heftier leaves on many plants. Two University of Washington scientists have discovered that plants with thicker leaves may exacerbate the effects of climate change because they would be less efficient in sequestering atmospheric carbon, a fact that climate change models to date have not taken into account. In addition to a weakening plant carbon sink, the simulations run by Abigail Swann, a UW assistant professor of atmospheric sciences and biology, and Marlies Kovenock, a UW doctoral student in biology, indicated that global temperatures could rise an extra 0.3 to 1.4 degrees Celsius beyond what has already been projected to occur by scientists studying climate change. Scientists don’t know why plants thicken their leaves when carbon dioxide levels rise in the atmosphere. But the response has been documented across many different types of plant species, such as woody trees; staple crops like wheat, rice and...
As climate changes, plants might not suck carbon from the air fast enough

As climate changes, plants might not suck carbon from the air fast enough

SOURCE: Michigan State University DATE: September 13, 2018 SNIP: Current climate change models might be overestimating how much carbon dioxide plants can suck from the atmosphere. Thanks to molecular research on photosynthesis done at the MSU-DOE Plant Research Laboratory (PRL), non-MSU atmospheric scientists have factored in a lesser understood photosynthetic limitation into their models. The result: models suggest that atmospheric carbon dioxide concentrations might increase more rapidly than previously expected. “When photosynthesis gets too much carbon dioxide, it can’t process it into sugars fast enough,” says Tom Sharkey, University Distinguished Professor at the PRL. “Photosynthesis cannot indefinitely increase its productivity levels. It reaches a ceiling, and more carbon dioxide won’t help. In fact, plants sometimes absorb less carbon dioxide as levels increase in the atmosphere.” “The prognosis is more alarming than we previously thought. We need to better understand TPU limitation, because it is affected by many factors. So far, we know the limitation is worse at high light levels, when temperatures are colder, and at high carbon dioxide...
Increase of plant species on mountain tops is accelerating with global warming

Increase of plant species on mountain tops is accelerating with global warming

SOURCE: Science Daily DATE: April 4, 2018 SNIP: Over the past 10 years, the number of plant species on European mountain tops has increased by five-times more than during the period 1957-66. Data on 302 European peaks covering 145 years shows that the acceleration in the number of mountain-top species is unequivocally linked to global warming. During the decade from 1957-66, the number of species on each of the 302 mountain tops increased by 1.1 species on average. Since then, the trend has accelerated: From 2007-16, on average 5.5 new species moved up to the 302 summits. The researchers have only been able to count the plant species that have already responded to the temperature rise and actually have moved upwards. They have not studied the number of species that might be on the way...
As ice retreats, frozen mosses emerge to tell climate change tale

As ice retreats, frozen mosses emerge to tell climate change tale

SOURCE: Science News DATE: October 26, 2017 SNIP: Some mosses in the eastern Canadian Arctic, long entombed in ice, are now emerging into the sunlight. And the radiocarbon ages of those plants suggest that summertime temperatures in the region are the warmest they’ve been in tens of thousands of years. As the planet warms and the ice retreats on Canada’s Baffin Island, the change is revealing plants long buried beneath the ice. And in some locations, the emerging plants last saw the sun at least 45,000 years ago — and possibly as much as 115,000 years ago. Paleoclimatologist Gifford Miller of the University of Colorado Boulder reported the finding October 22 at the Geological Society of America’s annual meeting. “We were stunned,” Miller said. Miller’s team has collected an impressive number of samples and their findings are very compelling, said geomorphologist Lee Corbett of the University of Vermont in Burlington, who was not involved in the study. “It truly is an indication that humans are pushing the climate into a new regime, one that modern, agriculture-based civilizations have never witnessed.” Originally, the researchers expected to find plants dating to medieval times, which would have suggested that the region is the warmest it’s been since the Middle Ages. But finding 3,700-year-old plants was a surprise, Miller said. And “we never anticipated we’d find plants 40,000 years old,” he added. “It’s a bit spooky because it provides quantitative evidence that the magnitude of summer warmth is already sufficient to melt all ice in the eastern Canadian Arctic. It’s just a matter of time...
Poison ivy on steroids: Another side of climate change

Poison ivy on steroids: Another side of climate change

SOURCE: Ottawa Citizen DATE: October 6, 2017 SNIP: An American forest scientist has identified a new and scary face of global warming for Ottawa residents: Not drought or pestilence, but bigger and badder poison ivy. Lee Frelich is a big name in the field of forecasting what climate change will do to forest species. He teaches at the University of Minnesota, and has been in the forest research business since the late 1970s. He knows Ontario’s forests too. And he says there’s firm evidence that poison ivy will thrive in our expected future climate. Climate change “will favour poison ivy quite dramatically,” he said in an interview. “Poison ivy is one of the few species that has a direct response to rising carbon dioxide...