Richard Harris

The Rio+20 Conference on Sustainable Development was the biggest United Nations conference ever, but it may be one of the biggest duds. It produced no major agreements — just a vaguely worded declaration that has been widely derided.

More than 45,000 people registered for the event in Rio de Janeiro, but diplomats couldn't even agree about the meeting's objective until 2:45 a.m. on Tuesday, just before heads of state and other high-level delegates started arriving in Rio.

The federal government could soon give the final go-ahead for Royal Dutch Shell to begin drilling for oil in the Arctic Ocean. Shell has spent $4 billion since 2007 to prepare for this work, and is hoping to tap into vast new deposits of oil.

But the plan to drill exploratory wells is controversial — opposed by environmental groups and some indigenous people as well.

Diplomats and activists from around the world are meeting in Rio de Janeiro this week to talk about how the planet's growing population can live better lives without damaging the environment. The Rio+20 meeting marks the 20th anniversary of the United Nations Earth Summit in Rio, a watershed meeting to address topics as diverse as climate change and biodiversity.

At this follow-up meeting, delegates hope to highlight an issue that was almost absent from the Earth Summit: making energy available to everyone in the world.

Imagine how tough life would be if raindrops weighed 3 tons apiece as they fell out of the sky at 20 mph. That's how raindrops look to a mosquito, yet a raindrop weighing 50 times more than one can hit the insect and the mosquito will survive.

How?

Put yourself in a mosquito's shoes — or rain boots — for a moment and step outside into a downpour of seemingly gigantic raindrops.

What snarky headline writer could resist a story about "hot tuna?" Or how about "tuna meltdown?"

Really, it seems just plain daffy to ignore a new study that says some Pacific bluefin tuna picked up traces of radioactive material from the Fukushima nuclear disaster last year and brought it across the Pacific Ocean.

Back when the dinosaurs ruled the Earth, some hardy bacteria took up residence at the bottom of the Pacific Ocean. Eighty six million years later, they're still there. And a new study says they're living out the most Spartan lifestyle known on this planet.

They're calling it a "rogue earthquake."

On April 11 of this year, one of the 10 biggest earthquakes ever recorded struck off the coast of Indonesia. It was felt from Bangladesh to Australia.

You may not have even heard of this magnitude 8.6 quake. It barely made the news in the U.S. because it did very little damage. Two people died, but there was no massive tsunami.

Head outside at sunset tonight and look up at the sky. If the full moon seems a tad larger than normal to you, that means one of two things: You are exceptionally perceptive, or you were already expecting to be dazzled, after hearing some of the buzz about this year's "supermoon."

It turns out that all full moons are not created equal. That's because the moon's orbit around the Earth isn't a perfect circle — it's an ellipse. And tonight, we're in luck.

A new study has some reassuring news about how fast Greenland's glaciers are melting away.

Greenland's glaciers hold enough water to raise sea level by 20 feet, and they are melting as the planet warms, so there's a lot at stake.

A few years ago, the Jakobshavn glacier in Greenland really caught people's attention. In short order, this slow-moving stream of ice suddenly doubled its speed. It started dumping a whole lot more ice into the Atlantic. Other glaciers also sped up.

Energy ministers from around the world met in London this week and got a scolding. The International Energy Agency warned the ministers that they are falling way behind in their efforts to wean the world from dirty sources of energy. Nations are nowhere near being on track to avert significant climate change in the coming decades.

It turns out that right now, just about everything is conspiring to make it harder to clean up the world's energy supply.

The Himalayas are sometimes called the world's "third pole" because they are covered with thousands of glaciers. Water from those glaciers helps feed some of the world's most important rivers, including the Ganges and the Indus. And as those glaciers melt, they will contribute to rising sea levels.

So a lot is at stake in understanding these glaciers and how they will respond in a warming world. Researchers writing in the latest issue of Science magazine make it clear they are still struggling at that task.

Filmmaker James Cameron recently reminded us of the wonders of the sea by diving solo in a submarine to the deepest spot in the ocean. Next year, if all goes as planned, a rather different expedition will take place 1,000 miles south of that dive: An Australian company will start mining for copper, gold, silver and zinc on the seafloor off the shore of Papua New Guinea.

Shell Oil plans to explore for petroleum off Alaska's north coast this summer. The native people of Alaska have a big stake in both oil revenue and environmental protection. That conflict has played out in recent trips by Inupiats to Washington, D.C., to argue their case.

The man who warned us that aerosol spray-cans could destroy the earth's protective ozone layer has died.

F. Sherwood Rowland, better known as Sherry Rowland, was a Nobel-prize winning chemist at the University of California, Irvine. And he didn't just keep to the laboratory: He successfully advocated for a ban on ozone-destroying chemicals called CFCs.

The earthquake and tsunami that hit Japan on March 11, 2011, lasted for many terrifying minutes. But the multiple nuclear meltdowns that followed created an emergency that lasted for weeks and a legacy that will last for decades.

Here's how the event unfolded. The tsunami knocked out power to the Fukushima Dai-ichi nuclear power plant. As a result, the cooling systems failed and three reactors melted down. Steam laced with radioactive material poured into the air. Water contaminated with radiation also flowed into the sea.

One year ago this Sunday, a 9.0 magnitude earthquake off Japan triggered a tsunami that killed 20,000 people. It also triggered multiple meltdowns at the Fukushima Dai-ichi nuclear power station, one of the worst nuclear disasters in history.

But health effects from radiation turn out to be minor compared with the other issues the people of Fukushima prefecture now face.

The wind power industry in this country has grown fast in recent years, but that could come to a screeching halt.

The industry depends on a federal subsidy to keep it competitive with other forms of electricity. It's a tax credit wind farms get for the power they produce. That credit expires at the end of the year, and it's not clear whether Congress will renew it.

The tax credit was initially created to encourage wind energy, since it is a clean and secure source of electricity. But these days the argument is all about jobs.

There's an old joke around newsrooms: News is something that happens to your editor.

If you'll pardon the self-indulgence, I'm going to take this truism one step further: News is what happened to me.

I was laid low the week before New Year's Day by a mysterious headache and a blazing sore throat. A few days later I lost my voice.

My doctors eventually pinpointed the cause by snaking a small camera down my nose. My left vocal fold (or vocal cord if you prefer) had stopped working. It was essentially paralyzed, other than the occasional twitch.

The Earth's continents are in constant motion. On at least three occasions, they have all collided to form one giant continent. If history is a guide, the current continents will coalesce once again to form another supercontinent. And a study in Nature now shows how that could come about.

You can think of continents as giant puzzle pieces shuffling around the Earth. When they drift apart, mighty oceans form. When they come together, oceans disappear. And it's all because continents sit on moving plates of the Earth's crust.

Ever wondered who the big greenhouse-gas emitters are in your neck of the woods? The answer is now just a click away.

The US Environmental Protection Agency today unveiled a new website that identifies most of the nation's biggest emitters of carbon dioxide, methane and other greenhouse gases. It lets you, for example:

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