Ancient seaweed that have been found growing in the deep sea are “living fossils”, researchers have reported.

The two types of seaweed, which grow more than 200m underwater, represent previously unrecognised ancient forms of algae, say the scientists.

As such, the algae could belong to the earliest of all known green plants, diverging up to one billion years ago from the ancestor of all such plants.

Details of the discovery are published in the Journal of Phycology.

“The algae occur in relatively deep marine waters – 210m, which is certainly deep for a photosynthetic organism,” Professor Frederick Zechman told the BBC.

“They can be found in shallower water but typically under ledges in low light.

Levi, Primo. The Periodic Table p. 231 (paperback)

After looking at the relationship between atmospheres and life a few dozen light years away, a billion years or so in the future and three billion years or more in the past, it’s time to look at the one in your lungs at the moment. Given that humans are changing the atmosphere at an unprecedented rate, what responses should we expect from the biosphere? And is there anything that we can do to make those responses work to human benefit?

For those in a hurry, the answers in brief: a) complicated ones; b) yes, at least a bit.

Human influence on the atmosphere takes many forms, but the most dramatic is the recent build-up of carbon dioxide, produced mostly by burning fossil fuels. Before the Industrial Revolution, the carbon dioxide level in the atmosphere was about 280 parts per million. Today, it is about 387 parts per million. Action to limit emissions might see the eventual level even off at 450 p.p.m., a target popular with greens and like-minded politicians – but only if such action were far more dramatic than any seen so far. While stressing that they would like to see such a plateau, or ideally, a lower one, few climate scientists see a stable 450 p.p.m. world as very likely. A world in which the pre-industrial level is doubled is a more likely one – and higher levels are far from out of the question.

Published: Thursday, May 28, 2009 – 16:24 in Earth & Climate

Researchers have conducted the first global analysis of the health and productivity of ocean plants, as revealed by a unique signal detected by a NASA satellite. Ocean scientists can now remotely measure the amount of fluorescent red light emitted by ocean phytoplankton and assess how efficiently the microscopic plants are turning sunlight and nutrients into food through photosynthesis. They can also study how changes in the global environment alter these processes, which are at the center of the ocean food web. Single-celled phytoplankton fuel nearly all ocean ecosystems, serving as the most basic food source for marine animals from zooplankton to fish to shellfish. In fact, phytoplankton account for half of all photosynthetic activity on Earth. The health of these marine plants affects commercial fisheries, the amount of carbon dioxide the ocean can absorb, and how the ocean responds to climate change.

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Attempts To Mimic A Plant’s Light-Harvesting And Water-Splitting Megamachinery
Sarah Everts

By David Pescovitz on High Energy

Every year, approximately 2.5 million exajoules of solar energy reach the Earth. That’s about 5,000 times the amount of energy consumed by people each year. The trick is collecting it and converting it into electricity cheaply and efficiently. Plants do a good job of that. Turns out scientists have been working on ways to imitate nature’s photosynthesis since 1912. And they’re still at it. This week, the scientific journal Chemical & Engineering News posted two deep articles on the subject. The first is about the molecular mysteries of photosynthesis, including whether it’s as efficient as one would expect from a process that has more than a couple billion years of evolution behind it. From the article, “Harnessing Light”:

“Water-splitting is key to the renewable production of hydrogen gas and other energy fuels, and doing so with inexpensive catalysts, as plants do a billion times per day, would be a huge step forward for solar power research. But the photosynthetic process has some other secrets, too, that scientists are only just figuring out, such as how photosynthetic organisms can tame light without suffering too much radiation damage, the plant equivalent of a sunburn…”

Evidence for wavelike energy transfer through quantum coherence in photosynthetic systems

Photosynthetic complexes are exquisitely tuned to capture solar light efficiently, and then transmit the excitation energy to reaction centres, where long term energy storage is initiated. The energy transfer mechanism is often described by semiclassical models that invoke ‘hopping’ of excited-state populations along discrete energy levels.

In his scheme, rich countries need to undertake the biggest reductions by 2030: an 87% cut for the UK, 88% for Germany, 83% for France, and 94% cuts for the United States, Canada, and Australia.