Tag Archives: climate changes

Environmental Issues: How True the Climate Changes Affecting Biodiversity

A changing climate has implications on biodiversity without any doubt. Species in the past have been sensitive to changes in the climate; that has been proved time and again by the fossilized remains and pollen distribution studies. It has been seen or can be concluded safely that climate changes have led to extinction of species in one area and colonization in another.

It is improbable that all species can or will be able to adapt to changing conditions specially the sudden changes. This leads to impact in ecosystem dynamics and also on community composition. (more…)

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Humans Have Love-Hate Relationship With the Environment

James Watson, a UA anthropologist, has published chapters describing how long-term environmental trends encourage stable adaptations within local environments.

Human/environment interactions have a history as long as the existence of our species on the planet.

Hominid ancestors began polluting their environment nearly 700,000 years ago with the control of fire, and humans have not looked back since.

The modern phenomenon of global warming is very likely the direct result of human pollution and destruction of the environment, said James Watson, a University of Arizona assistant professor in the School of Anthropology. (more…)

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North American Mammal Evolution Tracks with Climate Change

*Climate changes profoundly influenced the rise and fall of six distinct, successive waves of mammal species diversity in North America over the last 65 million years, shows a novel statistical analysis led by Brown University evolutionary biologists. Warming and cooling periods, in two cases confounded by species migrations, marked the transition from one dominant grouping to the next.*

PROVIDENCE, R.I. [Brown University] — History often seems to happen in waves — fashion and musical tastes turn over every decade and empires give way to new ones over centuries. A similar pattern characterizes the last 65 million years of natural history in North America, where a novel quantitative analysis has identified six distinct, consecutive waves of mammal species diversity or “evolutionary faunas.” What force of history determined the destiny of these groupings? The numbers say it was typically climate change.

“Although we’ve always known in a general way that mammals respond to climatic change over time, there has been controversy as to whether this can be demonstrated in a quantitative fashion,” said Christine Janis, professor of evolutionary biology at Brown University. “We show that the rise and fall of these faunas is indeed correlated with climatic change — the rise or fall of global paleotemperatures — and also influenced by other more local perturbations such as immigration events.” (more…)

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Thawing Permafrost Could Release Vast Amounts of Carbon and Accelerate Climate Change by the end of this Century

*New computer modeling study, led by a Berkeley Lab scientist, could help revise understanding of permafrost’s role in global warming*

Billions of tons of carbon trapped in high-latitude permafrost may be released into the atmosphere by the end of this century as the Earth’s climate changes, further accelerating global warming, a new computer modeling study indicates.

The study also found that soil in high-latitude regions could shift from being a sink to a source of carbon dioxide by the end of the 21st century as the soil warms in response to climate change. (more…)

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