Tag Archives: atmospheric co2

Asian Monsoon Much Older Than Previously Thought

Scientists originally thought the climate pattern began 22-25 million years ago as a result of the uplift of the Tibetan Plateau and the Himalaya Mountains. But UA researchers say that’s not going back far enough.

The Asian monsoon already existed 40 million years ago during a period of high atmospheric carbon dioxide and warmer temperatures, reports an international research team led by a University of Arizona geoscientist. (more…)

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Blades and Clades: Why Some Grasses Got Better Photosynthesis

Two groups — clades — of grasses that once had a common ancestry diverged. The PACMAD clade was predisposed to evolve a more efficient “C4” means of photosynthesis than grasses in the BEP clade. In a new study in the Proceedings of the National Academy of Sciences, a Brown-led team pinpoints the anatomical differences between the clades that led to the PACMAD’s tendency toward C4.

PROVIDENCE, R.I. [Brown University] — Even on the evolutionary time scale of tens of millions of years there is such a thing as being in the right shape at the right time. An anatomical difference in the ability to seize the moment, according to a study led by Brown University biologists, explains why more species in one broad group, or clade, of grasses evolved a more efficient means of photosynthesis than species in another clade. (more…)

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Impulsive Micromanagers Help Plants to Adapt, Survive

EAST LANSING, Mich. — Soil microbes are impulsive. So much so that they help plants face the challenges of a rapidly changing climate.

Jen Lau and Jay Lennon, Michigan State University biologists, studied how plants and microbes work together to help plants survive the effects of global changes, such as increased atmospheric CO2 concentrations, warmer temperatures and altered precipitation patterns. The results, appearing in the current issue of the Proceedings of the National Academy of Sciences, showed that microbes in the ground not only interact with plants, but they also prompt them to respond to environmental changes.

“We found that these changes in the plants happen primarily because of what global changes do to the belowground microbes rather than the plant itself,” said Lau, who works at MSU’s Kellogg Biological Station. “Drought stress affects microbes, and they, in turn, drive plants to flower earlier and help plants grow and reproduce when faced with drought.” (more…)

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Global Warming: New Research Emphasizes The Role of Global Economic Growth

ANN ARBOR, Mich.—It’s a message no one wants to hear: To slow down global warming, we’ll either have to put the brakes on economic growth or transform the way the world’s economies work.

That’s the implication of an innovative University of Michigan study examining the evolution of atmospheric CO₂, the most likely cause of global warming.

The study, conducted by José Tapia Granados and Edward Ionides of U-M and Óscar Carpintero of the University of Valladolid in Spain, was published online in the peer-reviewed journal Environmental Science and Policy. It is the first analysis to use measurable levels of atmospheric carbon dioxide to assess fluctuations in the gas, rather than estimates of CO₂ emissions, which are less accurate. (more…)

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Confidence in Climate Data: Using 3 Million-Year-Old Records

How do we understand what’s happening today by looking back millions of years?

Scientists are looking at what climate conditions were like 3.3 to 3 million years ago, during a geologic period known as the Pliocene, and they are confident in the accuracy of their data.

The Pliocene is the most recent period of sustained global warmth similar to what is projected for the 21st century. Climate during this time period offers one of the closest analogs to estimate future climate conditions. (more…)

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Projected Losses of Arctic Sea-Ice and Polar Bear Habitat may be Reduced if Greenhouse Gas Emissions are Stabilized

ANCHORAGE, Alaska – Sea-ice habitats essential to polar bears would likely respond positively should more curbs be placed on global greenhouse gas emissions, according to a new modeling study published in the journal, Nature

The study, led by the U.S. Geological Survey, included university and other federal agency scientists. The research broke new ground in the “tipping point” debate in the scientific community by providing evidence that during this century there does not seem to be a tipping point at which sea-ice loss would become irreversible.  (more…)

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