White House unveils climate change report with 'urgent' call for action – live

We're going to wrap up our live blog coverage for the day.

My colleague Alan Yuhas (@AlanYuhas) will cover the TV meteorologists' interviews with the president separately. Portions of those interviews are expected to air on the evening newscasts at 6pm ET, with transcripts to follow.

Please visit the Guardian US home page, beginning in about an hour, for further coverage.

Also there: Jim Gandy of WLTX-TV in Columbia, South Carolina:

Also there: John Morales of NBC 6 Miami:

Also at the White House to speak with the president today: Ginger Zee of ABC News.

From the comments:

Scientists warn sea levels could rise six feet by 2100

Currently it is rising at 3mm a year which is about 1 foot per hundred years

demagogue806 May 2014 7:32pm

It's a good point, that the lowest projections of sea level rising show another 1-4 feet in this century. But then there are the "wider range of scenarios", from the report:

Water expands as it warms, causing global sea levels to rise; melting of land-based ice also raises sea level by adding water to the oceans. Over the past century, global average sea level has risen by about 8 inches. Since 1992, the rate of global sea level rise measured by satellites has been roughly twice the rate observed over the last century, providing evidence of acceleration. Sea level rise, combined with coastal storms, has increased the risk of erosion, storm surge damage, and flooding for coastal communities, especially along the Gulf Coast, the Atlantic seaboard, and in Alaska. Coastal infrastructure, including roads, rail lines, energy infrastructure, airports, port facilities, and military bases, are increasingly at risk from sea level rise and damaging storm surges. Sea level is projected to rise by another 1 to 4 feet in this century, although the rise in sea level in specific regions is expected to vary from this global average for a number of reasons. A wider range of scenarios, from 8 inches to more than 6 feet by 2100, has been used in risk-based analyses in this report. In general, higher emissions scenarios that lead to more warming would be expected to lead to higher amounts of sea level rise. The stakes are high, as nearly five million Americans and hundreds of billions of dollars of property are located in areas that are less than four feet above the local high-tide level.

A UN report on climate change released in April provided a global take on the trends and threats found in the National Climate Assessment. Like the NCA, the UN report emphasized that climate change is no longer a phenomenon to be anticipated – it's happening today, now.

The UN report rested on years of work by hundreds of specializing scientists, delving into the risks to civilization from climate change – our food supply, our habitat, our health – with unprecedented specificity. The report, produced by the Intergovernmental Panel on Climate Change (IPCC), involved the participation of 271 officials from 115 countries.

The White House launch event has wrapped. Stay tuned for the results of the president's interview with the TV meteorologists.

Here's the first laugh/applause line of the afternoon: "Who says the White House can't build a great web site?"

It's true, it's a good site, check it out.

Al Roker of the Today Show appears to have been one of the TV weather personalities to "interview" president Barack Obama at the White House today.

The White House is hoping that local and national TV talent can help bring the story of climate change to the American public.

A transcript of the conversation will be made available at 5pm, the White House says.

The news site Vox has posted some graphics from the climate assessment:

The next panelist is a county commissioner in Broward county in South Florida. "We have streets that are underwater every time there's a full moon," she says, vividly.

A second panel appears at the White House event. The panel, which is to focus on recommended next steps, is chaired by TC Richmond, a vice-chair of the National Climate Assessment advisory committee.

"We are really at least a decade behind in thinking in detail about adaptation, compared to mitigation," says Rosina Bierbaum of the University of Michigan. Fifteen states have adaptation plans "and another dozen are really thinking hard about it."

"Many cities are already encountering flooding, heat waves, storm surges, and air conditioning demands increasing," she says. "Going forward, cities, states, and businesses – all will need localized, regularized information delivered to them." The federal government is "stepping up" to provide that, she says, in apparent reference to the NOAA.

Some climate change skeptics argue that whether the weather is changing, it certainly isn't the humans' fault.

Today's report calls that argument out as pure bushwa:

Multiple lines of independent evidence confirm that human activities are the primary cause of the global warming of the past 50 years. The burning of coal, oil, and gas, and clearing of forests have increased the concentration of carbon dioxide in the atmosphere by more than 40% since the Industrial Revolution, and it has been known for almost two centuries that this carbon dioxide traps heat. Methane and nitrous oxide emissions from agriculture and other human activities add to the atmospheric burden of heat-trapping gases. Data show that natural factors like the sun and volcanoes cannot have caused the warming observed over the past 50 years. Sensors on satellites have measured the sun’s output with great accuracy and found no overall increase during the past half century. Large volcanic eruptions during this period, such as Mount Pinatubo in 1991, have exerted a short-term cooling influence. In fact, if not for human activities, global climate would actually have cooled slightly over the past 50 years. The pattern of temperature change through the layers of the atmosphere, with warming near the surface and cooling higher up in the stratosphere, further confirms that it is the buildup of heat-trapping gases (also known as “greenhouse gases”) that has caused most of the Earth’s warming over the past half century.

Concur.

Meanwhile...

Next up at the White House event is Kathryn Sullivan, the administrator of the National Oceanic and Atmospheric Association (NOAA) – and the first American woman to walk in space.

60% of Americans say global warming is a serious problem and even more say that they see evidence of global warming in their own lives, she says.

"The question now is how do we ensure that this new information leads to more informed and more dynamic and dramatic action?" Sullivan says. "...The challenge before us now is the take this information off the pages... and actually connect it" to local communities and businesses.

The White House panel is asked what gives them hope that the worst effects of climate change can be avoided.

"We as Americans have shown through history that we know how to solve problems," one says, seemingly ignoring the global nature of the... weather.

"This nation is very weather-conscious," another says. "As more people see these changes, they are talked about... I think there's very much hope there in terms of trying to reach out and educate the broad populace."

The panelists seem to be describing their hope for creating workable evasive action plans to respond to extreme weather, as opposed to creating new plans for minimizing the release of heat-trapping gasses.

"We're slow to get going... but once we get started, change can happen," says a third. He mentions practical measures that are needed such as heat wave action plans, elevating critical infrastructure and increasing the size of culverts and drainage pipes.

"More interest in local foods and reducing the number of food-miles," a fourth panelist says.

"The thing that gives me the greatest hope are you all," says a fifth, referring to the audience. "That to me is the greatest hope. And that's one thing we don't do a good job yet of putting into climate models. The human spirit is not well-modeled."

In the northeast, the amount of rain dumped in major storms has climbed 71 percent since the 1950s, the report says. At the White House event, panel member Radley Horton of the Northeast Climate Science Center puts it like this:

For some places like New York City, what had been a one-in-a-hundred-year event becomes something you'd just expect over the lifetime of a typical mortgage.

Where do you live? The region-by-region breakdown of climate change and its effects is worth a read. The pictures are beautiful too – visit the section here. Here's a quickie overview:

Northeast

Heat waves, coastal flooding, and river flooding will pose a growing challenge to the region’s environmental, social, and economic systems. This will increase the vulnerability of the region’s residents, especially its most disadvantaged populations.

Southeast

Sea level rise poses widespread and continuing threats to both natural and built environments and to the regional economy.

Midwest

In the next few decades, longer growing seasons and rising carbon dioxide levels will increase yields of some crops, though those benefits will be progressively offset by extreme weather events. Though adaptation options can reduce some of the detrimental effects, in the long term, the combined stresses associated with climate change are expected to decrease agricultural productivity.

Great Plains

Rising temperatures are leading to increased demand for water and energy. In parts of the region, this will constrain development, stress natural resources, and increase competition for water among communities, agriculture, energy production, and ecological needs.

Southwest

Snowpack and streamflow amounts are projected to decline in parts of the Southwest, decreasing surface water supply reliability for cities, agriculture, and ecosystems.

Northwest

Changes in the timing of streamflow related to changing snowmelt have been observed and will continue, reducing the supply of water for many competing demands and causing far-reaching ecological and socioeconomic consequences.

Alaska

Arctic summer sea ice is receding faster than previously projected and is expected to virtually disappear before mid-century. This is altering marine ecosystems and leading to greater ship access, offshore development opportunity, and increased community vulnerability to coastal erosion.

Hawai'i

Warmer oceans are leading to increased coral bleaching events and disease outbreaks in coral reefs, as well as changed distribution patterns of tuna fisheries. Ocean acidification will reduce coral growth and health. Warming and acidification, combined with existing stresses, will strongly affect coral reef fish communities.

Rural communities

Rural communities are highly dependent upon natural resources for their livelihoods and social structures. Climate change related impacts are currently affecting rural communities. These impacts will progressively increase over this century and will shift the locations where rural economic activities (like agriculture, forestry, and recreation) can thrive.

Coasts

Coastal lifelines, such as water supply and energy infrastructure and evacuation routes, are increasingly vulnerable to higher sea levels and storm surges, inland flooding, erosion, and other climate-related changes.

What's new in this assessment? Satellite data since the early 1990s show that sea level rises have accelerated in the last decades, including on the Atlantic coast north of Cape Hatteras in North Carolina, the speaker says.

The sea level rise that preceded Hurricane Sandy, he says, meant that the storm surge got much further inland than it otherwise would have.

"The sleeping giant... has been ice in the major ice sheets of Greenland and the Antarctic... the giant is no longer asleep," he says. How quickly the sheets melt will determine how fast the sea rises.

Note: This post originally referred to "Arctic" ice sheets, when the scientist was referring to ice sheets in the Antarctic. The faster disappearance of sea ice in the Arctic is also of concern to climate scientists.

"All Americans will find things that matter to them in this report," the speaker continues.

For decades we have been collecting the dots. Now we are connecting the dots. The picture is clear, and it is stark.

The next speaker at the White House says he wants to repeat the report's top line: "Climate change, once thought as a problem for the future, has moved firmly into the present."

The take-home message is, it's happening now, and we need to pay attention.

Dr Holdren, the presidential science adviser, begins the White House event, calling this "the most transparent climate assessment ever." That rings a bell – but in the case of the climate report it seems true. The report has more than 300 authors and underwent an extensive peer review, including by the National Academy of Sciences, other scholars and the public.

Holdren is running through some of the main findings of the climate assessment. He mentions how climate change has registered differently in different regions across the United States, a point summarized in the assessment overview:

Some of the changes discussed in this report are common to many regions. For example, large increases in heavy precipitation have occurred in the Northeast, Midwest, and Great Plains, where heavy downpours have frequently led to runoff that exceeded the capacity of storm drains and levees, and caused flooding events and accelerated erosion. Other impacts, such as those associated with the rapid thawing of permafrost in Alaska, are unique to a particular U.S. region. Permafrost thawing is causing extensive damage to infrastructure in our nation’s largest state.

Some impacts that occur in one region ripple beyond that region. For example, the dramatic decline of summer sea ice in the Arctic – a loss of ice cover roughly equal to half the area of the continental United States – exacerbates global warming by reducing the reflectivity of Earth’s surface and increasing the amount of heat absorbed. Similarly, smoke from wildfires in one location can contribute to poor air quality in faraway regions, and evidence suggests that particulate matter can affect atmospheric properties and therefore weather patterns. Major storms and the higher storm surges exacerbated by sea level rise that hit the Gulf Coast affect the entire country through their cascading effects on oil and gas production and distribution.

The report's region-by-region breakdown is here.

The White House is planning to live stream a "National Climate Assessment Event" to begin any moment now. Click here to watch or see it below (technical issues with the embed code; please click through to view the event, which has just begun).

Here is a video of Dr. John Holdren, presidential science adviser, introducing the new National Climate Assessment. “This assessment is the most comprehensive and authoritative account ever about how climate has been changing in the United States, how it’s projected to continue to change in the future, and what can be done…” Holdren says.

The report is built on “unprecedented detail” on every geographic region of the United States, he says:

Holdren:

"Scientists who study climate change confirm that these [US] phenomena are consistent with the ongoing changes in global climate, which we know with very high confidence are being caused mainly by the increase of atmospheric carbon dioxide and other heat-trapping gases released by human activities."

The US Global Change Research Program, which is overseen by the executive office of the president, has gone to great lengths to make the new National Climate Assessment accessible and inviting for readers online.

The online version of the report boasts all the features of a fancy new interactive produced in a big newsroom. Animations, continuous scrolling, interactive charts and graphics – it's all in there.

Below, for example, is a screen grab of a slidable interactive graphic depicting the effects of elevated ocean acidity on a pteropod, an essential part of the marine food chain. View the interactive graphic here, and then see the full report online.

From the report:

In addition to causing changes in climate, increasing levels of carbon dioxide from the burning of fossil fuels and other human activities have a direct effect on the world’s oceans. Carbon dioxide interacts with ocean water to form carbonic acid, increasing the ocean’s acidity. Ocean surface waters have become 30% more acidic over the last 250 years as they have absorbed large amounts of carbon dioxide from the atmosphere. This ocean acidification makes water more corrosive, reducing the capacity of marine organisms with shells or skeletons made of calcium carbonate (such as corals, krill, oysters, clams, and crabs) to survive, grow, and reproduce, which in turn will affect the marine food chain.

Good afternoon and welcome to our live blog coverage of the release of a landmark National Climate Assessment report on climate change in the USA.

To highlight the report and its findings, the White House is hosting a series of events this afternoon, including a Rose Garden colloquy called “Weather from the White House”, billed as a conversation between the president and “local and national meteorologists”.

Average temperatures in the United States have risen nearly two degrees since 1895 and could rise 10 more by 2100, the report says, and sea levels could rise by more than six feet. The report predicts economic and human damage from the changing climate and underscores “the need for the American people to prepare for and respond to [the] far-reaching implications”:

Americans are noticing changes all around them. Summers are longer and hotter, and extended periods of unusual heat last longer than any living American has ever experienced. Winters are generally shorter and warmer. Rain comes in heavier downpours. People are seeing changes in the length and severity of seasonal allergies, the plant varieties that thrive in their gardens, and the kinds of birds they see in any particular month in their neighborhoods.

They’re not just making it up – the report is a distillation of the largest batch of US climate data ever, collected by more than 300 experts working over decades in every corner of the country. Neither is the report an Obama administration tactic to distract attention from Benghazi; it was ordered up in a law signed by president George HW Bush.

“It is notable that as these data records have grown longer and climate models have become more comprehensive, earlier predictions have largely been confirmed,” says the report:

The only real surprises have been that some changes, such as sea level rise and Arctic sea ice decline, have outpaced earlier projections.

What is new over the last decade is that we know with increasing certainty that climate change is happening now.