Brighter model for global warming

50443248 — Wed, 25 Jul 2007 11:08:56 -0400

To environmental chemist Scot Martin, chemistry is a way of understanding the Earth and some of its most pressing problems.
From global warming to heavy metal pollution in groundwater, Martin, named Gordon McKay Professor of Environmental Chemistry last July, is using the tools of chemistry to shed light on how natural processes interact with human activities to affect the environment.

Researchers close in on date of critical rise in Earth's oxygen

70652986 — Mon, 26 Mar 2007 05:35:43 -0400

Findings by Harvard researchers and colleagues narrow the range of possible dates for a critical change in the Earth's atmosphere. Scientists had previously believed oxygen first appeared sometime between 2.45 billion and 2.22 billion years ago, a span of about 230 million years. The new findings narrow that window dramatically - to about 130 million years. "It's a fascinating transition, from a physical, chemical, and biological point of view," said Heinrich D. Holland, Harry C. Dudley Research Professor of Economic Geology, who, with postdoctoral fellow Andrey Bekker and colleagues from other institutions, conducted the research. The increase in oxygen allowed the development of early oxygen-using creatures and sowed the seeds for the eventual development of large land animals, an event scientists believe occurred after a second large increase in oxygen more than a billion years later. Whatever the cause, Bekker, Holland, and their colleagues, writing in the Jan. 7, 2004, issue of Nature, detailed their investigation of a black shale, a sedimentary rock thought to have been deposited 2.32 billion years ago in a shallow marine river delta. Researchers examined rock cores drilled by mining companies exploring South Africa's rich mineral resources.

all Heinrich Holland stories

Brighter model for global warming

Researchers close in on date of critical rise in Earth's oxygen