Selected category: Oceans

Six Climate Tipping Points: How Worried Should We Be?

One of the biggest fears about climate change is that it may be triggering events that would dramatically alter Earth as we know it.

Known to scientists as “tipping events,” they could contribute to mass extinction of species, dramatic sea level rise, extensive droughts and the transformation of forests into vast grasslands – among other upheavals our stressed world can ill afford.

Here are the top six climate events scientists worry about today.

1. The Arctic sea ice melts

The melting of the Arctic summer ice is considered to be the single greatest threat, and some scientists think we’ve already passed the tipping point.

As sea ice melts and the Arctic warms, dark ocean water is exposed that absorbs more sunlight, thus reinforcing the warming. The transition to an ice-free Arctic summer can occur rapidly – within decades – and this has geopolitical implications, in addition to a whole ecosystem being disrupted.

Photo: Smudge 900)

2. Greenland becomes ice-free

The warming of the Arctic may also render Greenland largely ice-free. While Greenland’s ice loss will likely reach the point of no return within this century, the full transition will take at least a few hundred years.

The impacts of the Greenland ice melt is expected to raise sea levels by up to 20 feet.

Half of the 10 largest cities in the world, including New York City, and one-third of the world’s 30 largest cities are already threatened by this sea level rise. Today, they are home to nearly 1.8 billion people.

Other vulnerable American cities include Miami, Norfolk and Boston.

Photo: siralbertus

3. The West Antarctic ice sheet disintegrates

On the other side of Earth, the West Antarctic ice sheet is also disintegrating. Because the bottom of this glacier is grounded below sea level, it’s vulnerable to rapid break-up, thinning and retreat as warm ocean waters eat away at the ice.

Scientists expect the West Antarctic ice sheet to “tip” this century, and there is evidence that it already began happening in 2014.

However, the entire collapse of the glacier, which would raise sea level by 16 feet, could take a few hundred years.

Photo: BBC World Service

4. El Niño becomes a more permanent climate fixture

The oceans absorb about 90 percent of the extra heat that is being trapped in the Earth system by greenhouse gases. This could affect the ocean dynamics that control El Niño events.

While there are several theories about what could happen in the future, the most likely consequence of ocean heat uptake is that El Niño, a natural climate phenomenon, could become a more permanent part of our climate system.

That would cause extensive drought conditions in Southeast Asia and elsewhere, while some drought-prone areas such as California would get relief.

The transition is expected to be gradual and take around a century to occur – but it could also be triggered sooner.

Photo: Austin Yoder

 5. The Amazon rain forest dies back

Rainfall in the Amazon is threatened by deforestation, a longer dry season, and rising summer temperatures.

At least half of the Amazon rainforest could turn into savannah and grassland, which – once triggered – could happen over just a few decades. This would make it very difficult for the rainforest to reestablish itself and lead to a considerable loss in biodiversity.

However, the reduction of the Amazon ultimately depends on what happens with El Niño, along with future land-use changes from human activities.

Photo: World Bank

 6. Boreal forests are cut in half

Increased water and heat stress are taking a toll on the large forests in Canada, Russia and other parts of the uppermost Northern Hemisphere. So are forest disease and fires.

This could lead to a 50-percent reduction of the boreal forests, and mean they may never be able to recover. Instead, the forest would gradually transition into open woodlands or grasslands over several decades.

This would have a huge impact on the world’s carbon balance because forests can absorb much more carbon than grasslands do. As the forest diminishes, the climate will be affected as will the Earth’s energy balance.

However, the complex interaction between tree physiology, permafrost and fires makes the situation tricky to understand.

Photo: Gord McKenna

Other concerns…

As if that’s not enough, there are a few other tipping events that scientists are also concerned about, but they are even more complex and harder to predict. Examples of such events include the greening of the Sahara and Sahel, the development of an Arctic ozone hole and a chaotic Indian summer monsoon.

How do we keep from tipping over?

We know from measurements that the Earth has had many climate-related tipping events throughout its history. Today’s situation is different, because humans are now driving these changes and the warming is occurring at a faster rate.

But as humans we also have the power to change the trajectory we’re on – possibly in a matter of a few years. We think we know how.

Also posted in Arctic & Antarctic, Basic Science of Global Warming, Extreme Weather, Greenhouse Gas Emissions, Plants & Animals| Read 1 Response

New report: How climate change is impacting where you live

The National Climate Assessment (NCA) report, prepared by the U.S. Global Change Research Program, is essentially the U.S. equivalent of the Intergovernmental Panel on Climate Change (IPCC): Using the best available science, over 300 experts synthesized current understanding of observed and future climate changes and impacts, particularly in the U.S. The third ever NCA was released today, and concludes beyond a reasonable scientific doubt that Americans are being affected by climate change.

Among the findings:

  • U.S. average temperatures have increased by 1.3 to 1.9ºF since record-keeping began in 1895, and most of this warming has occurred since 1970
  • Heavy precipitation has increased in many parts of the country
  • Extremes such as heat waves, droughts, floods, and North Atlantic hurricanes are more frequent and/or intense
  • Summer sea ice in the Arctic has halved since record-keeping began in 1979
  • Sea level rise has increased coastal erosion and storm surge damage

These changing conditions produce a variety of tangible stresses on society by affecting human health, water resources, agriculture, energy, infrastructure, and natural ecosystems. The particular impacts vary by region, but no corner of the country is immune to the change.

So what’s happening where you live?

Source: National Climate Assessment

Unless we take immediate action to curb our emissions of heat-trapping gases, the foreseeable future will be plagued by further warming and worsening impacts. The good news is that because we know what the cause is, we also know what is needed in order to stabilize our planet. We must come together now—locally, nationally, and internationally—and work towards a better future.

This post first appeared on our EDF Voices blog

Also posted in Arctic & Antarctic, Basic Science of Global Warming, Extreme Weather, Science| Comments are closed

Antarctica's Glacial Melt

There should no longer be any doubt. Climate change is here, and it is happening. 26,000 broken heat records this summer speak for themselves.

Extreme weather events hit home. Another consequence of climate change, by contrast – rising sea levels – often seems far away and far off.

“Far away” is easily dismissed. U.S. coasts are as much in danger as sea shores anywhere else on the planet.

"Far off” often seems tougher to address. After all, seas have only risen by inches so far. Projections say we could see three or more feet by the end of the century.

Even right now, though, we’re seeing the evidence of sea level rise. Antarctic ice sheets have been melting to the tune of 24 cubic miles of melt water per year, every year, since 2002.

That is a huge number, but a fairly abstract number. So The Globalist designed a quiz to make the giant quantity feel a bit more real. EDF was honored to help with the research for the quiz.

See if you can answer the question:

If you were to take the melt-off from Antarctica's ice sheets over the past decade (2002 to 2012) and pour it into a California-sized Jell-O mold, how high would the water rise?

The right answer might surprise you. Hint: Think Paul Sturgess, the world's tallest professional basketball player.

And check out The Globalist quiz for more details.

Also posted in Arctic & Antarctic, Extreme Weather, News, Science| Read 1 Response

Somewhere Over the Gulf Coast: A “Glee” and BP Oil Disaster Mashup


From a comfortable distance – in our classrooms, around our water coolers, through pictures on TV or newspapers – the BP oil disaster is depressing and horrific.

But up close where every breath you take fills your mouth, nose, and lungs with the toxic mix of oil and industrial chemicals, where you talk with resilient and proud locals and hear their frustration, anger, and concern, where the disturbing and unforgettable scenes of a precious and fragile ecosystem in crisis are just seared into your mind – all of it is just so bad, so repugnant, so wrong in the most profound way.

Two days in the Gulf of Mexico left me enraged – and deeply resolved. Both the widespread damage and the inadequacy of the response effort exceeded my worst fears.

Seeing terns and gulls sitting on the oil-soaked booms that were supposed to be protecting their fragile island marshes – booms that had been blown or washed ashore – may have been the ultimate symbol of the devastation unfolding in the Gulf.

Or maybe it was the lone shrimp trawler, aimlessly circling off the coast, dragging a saturated gauze-like boom behind it, accomplishing nearly nothing.

Or maybe it was the desperation of the fishermen whose livelihoods had been snatched away by BP’s recklessness – and yet want nothing more than to see the moratorium on drilling lifted so their economies don’t dry up, as well.

I’d spent a full day on the Gulf and we ended up soaked in oily water and seared by the journey into the heart of ecological darkness.

By Tuesday night, I was home. My throat burned and my head was foggy and dizzy as I showed my pictures and my flip-camera video to my wife, Fran, and my 13-year-old daughter, Nicole, on the TV in the family room.

Images of the gooey peanut-butter colored oil and the blackened wetlands flashed by. Pictures of dolphins diving into our oily wake and Brown Pelicans futilely trying to pick oil off their backs popped on the screen. And, out of nowhere, Nicole put on the music from the season finale of Glee.

With all these horrific images on the screen, she had turned on the show’s final song of the year, “Somewhere Over The Rainbow.” The song, a slow, sweet, ukulele and guitar-driven version, couldn’t have added a deeper sense of tragic irony.

I choked up. And then that resolve kicked in: I wanted anyone/everyone to see what our addiction to oil had done to the Gulf and to contrast that with the sense of hope and possibility that “Somewhere” exudes.

Long story short, last weekend, Peter Rice, Chairman of Fox Networks Entertainment, gave Environmental Defense Fund the green light to use the song. The pictures you’ll see were shot by two incredibly talented EDF staffers, Yuki Kokubo and Patrick Brown – and a few are mine.

The inspiration was Nicole’s. This is for her, and for all of our kids – and theirs to come.

David Yarnold is executive director of Environmental Defense Fund.

Also posted in Climate Change Legislation, News, Policy, Science| Read 1 Response

Check out this week’s Expert Q &A on the Gulf oil spill

As part of EDF’s mission to keep the public informed of the largest challenges facing the environment, we have put together a series called Expert Q&A. The goal is to get simple answers to pressing questions from the people who know the issues inside and out, our EDF staff experts.

This week the expert Q & A focuses on the gulf oil spill and how the disaster will affect our chances of passing the recently released climate bill, the American Power Act.

The expert in question and being questioned is Steve Cochran, the director of our National Climate Campaign.

In answer to the question of whether a spill in the Gulf was inevitable, Steve responds:

“We have a saying where I grew up: If you continue to load the gun, God will provide the drunk or the fool who is going to pull the trigger. There are over 3,000 operating wells in Gulf. I know firsthand how great the pressure is to produce at all costs, even at the expense of cutting corners on safety. Sad to say, it was only a matter of time before it caught up with us.”

When asked about how to prevent further disasters, Steve explains that:

“It is going to happen again even if we never drilled another new well.

But we can do several things to protect ourselves. We can require that the emergency response infrastructure be in place – I’m talking warehouses filled with booms and equipment – so when there is another spill we can respond more quickly. It’s incredible to me that this doesn’t exist today.

Second, we can make it more expensive for oil companies to cut back on safety. We have to make sure that oil companies are held accountable, pay for the protections and pay for the clean up and the carbon pollution associated with these products.

Making the polluter pay will do more than anything else we can do to reduce the risk of exposure to these pollutants. We can mandate it, we should, we can require it, and we should. But, making them pay for it, making sure they know the dollars will come out of their pocket if they make a mistake, that's the key.”

Steve also shares some sage words on how passing a smart climate bill focused on public safety is essential to helping us transition into a clean energy economy.

“There are two pieces to it. One, I don't think we should have any discussion about new drilling until we have the safeguards and protections in place that give us more confidence that we won't face what we are facing right now. Without that I don't know how to have that conversation. It's hard to turn on the television every day and say we know how to do this well enough. So for the short-term view we have to focus on the safety and precautions and see if we can put a system in place that gives people some confidence.

The second piece of course is the critical need to cap our carbon pollution, which will create powerful economic incentives to transition to a clean energy economy.”

Read the full Q & A here.

Also posted in Climate Change Legislation, News| Comments are closed

Coral Reefs in Decline

Rod FujitaRod Fujita, Ph.D., is a scientist in the Oceans program at Environmental Defense Fund.

Coral reef with sea urchins in Hawaii. Photo by Mila Zinkova.Coral reefs aren't just pretty places for scuba divers (although they do bring in billions of tourist dollars). These rich ecosystems supply the inhabitants of coral reef countries with the fish that they depend on as their main source of protein. Coral reefs, like rainforests, are also treasure troves of biodiversity that may hold the keys to fighting diseases like cancer and arthritis. Human wellbeing is tightly bound to the health of coral reefs.

Unfortunately, coral reefs are in trouble, and climate change plays a major role.

Read More »

Posted in Oceans| Read 5 Responses
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