Author Archives: Ilissa Ocko

It’s now, it’s us, it’s not over – the top 7 takeaways from the new climate change report

Earth as seen from a NOAA weather satellite. Photo: NASA

The U.S. government recently released the Climate Science Special Report (CSSR) – the work of fifty climate science experts who compiled and analyzed the latest knowledge about the physical science of climate change from more than 1,500 scientific journal articles and reports.

The CSSR is often referred to as the first volume of the Fourth National Climate Assessment. National Climate Assessments have been Congressionally mandated since 1990 to be prepared every four years. The second and final volume of the Fourth National Climate Assessment will focus on societal impacts and will be released in 2018.

The CSSR is packed with valuable and scientifically robust information – but it’s almost 600 pages long. If you don’t have time to read it all, don’t worry. We quote some of the most important, and most alarming, facts below.

Here are some of the major takeaways of the CSSR:

It’s now

  • Global average temperature since 1900 is the warmest in the history of modern civilization. Global annually averaged surface air temperature has increased by about 1.8 degrees Fahrenheit (1.0 degrees Celsius) over the last 115 years (1901 to 2016).
  • Sea level rise is accelerating and has already impacted dozens of U.S. cities. Globally averaged sea level has risen by about 7 to 8 inches since 1900, with almost half (about 3 inches) of that rise occurring since 1993. The incidence of daily tidal flooding is accelerating in more than 25 Atlantic and Gulf Coast cities.
  • Several extreme weather and climate events are increasing in intensity and frequency across the U.S. and the world. Heavy rainfall is increasing in intensity and frequency, heatwaves have become more frequent in the United States since the 1960s, and the incidence of large forest fires in the western United States and Alaska has increased since the early 1980s. However, extreme cold temperatures and cold waves are less frequent.
  • Earlier spring melt and reduced snowpack are affecting water resources in the western U.S.

It’s us

  • There is no convincing alternative explanation supported by observational evidence that warming over the last century is caused by anything other than human activities. It is extremely likely that human activities, especially emissions of greenhouse gases, are the dominant cause of the observed warming since the mid-20th century.

It’s not over

  • Without major reductions in emissions, annual average global temperature relative to preindustrial times could increase by 9 degrees Fahrenheit (5 degrees Celsius) or more by the end of this century. With significant reductions in emissions, the increase in annual average global temperature could be limited to 3.6 degrees Fahrenheit (2 degrees Celsius) or less.
  • With further warming comes further sea level rise. Global average sea levels are expected to continue to rise — by at least several inches in the next 15 years and by one to four feet by 2100. A rise of as much as eight feet by 2100 cannot be ruled out. Sea level rise will be higher than the global average on the East and Gulf Coasts of the United States.

The CSSR should put any doubts about whether climate change is a serious threat to rest. The report makes it crystal clear that it is – and that we need to act before it gets worse.

Posted in Basic Science of Global Warming, Extreme Weather, Science| Comments are closed

The Clean Power Plan’s enormous climate benefits – in one graphic

In addition to the vital public health benefits it offers, the Clean Power Plan is the nation’s most significant action to date to address climate change’s number one culprit – heat-trapping carbon dioxide emissions.

Now, EPA Administrator Scott Pruitt is trying to revoke the Clean Power Plan. Here’s a look at the enormous benefits we could lose.

When the Clean Power Plan is fully in place by 2030, the avoided annual carbon dioxide emissions relative to business-as-usual (350 million metric tons) are equivalent to preventing:

  • 40 billion gallons of gasoline consumed, or
  • 380 billion pounds of coal burned, or
  • 810 million barrels of oil consumed, or
  • 850 billion miles driven by an average car.

In order to get the same climate benefits that the Clean Power Plan would deliver, we would need to:

  • Replace 12 billion incandescent light bulbs with LEDs, or
  • Take 75 million cars off the road

Click to enlarge

 

Posted in Basic Science of Global Warming, Clean Power Plan, Greenhouse Gas Emissions, News, Science| Read 1 Response

Puerto Rico a tragic reminder of why climate action cannot wait

Source: FEMA

The disaster unfolding in Puerto Rico is heartbreaking – and a call for action.

Our focus as a nation must be to help our fellow citizens as quickly as possible, but also to do what we can to prevent similar catastrophic events in the future.

With three Category 4 hurricanes – undoubtedly worsened by climate change – making landfall and wreaking havoc in the United States in just a few weeks, we’ve had three wake-up calls. Climate change is an urgent issue that must be addressed now.

By continuing to ignore the fundamental threat that global warming poses today, however, the Trump administration is setting up Puerto Rico and the rest of the Hurricane Alley region for more disasters and tragedies.

It’s akin to a doctor who treats the symptoms of a patient while ignoring a dangerous, underlying disease. It makes for a bad doctor – and America expects more than that.

Puerto Ricans are living climate change

Considered a “canary in the coal mine” for climate change, the Commonwealth of Puerto Rico has been feeling the consequences of a warming world for some time already.

Its beaches are retreating with some homes in the capital of San Juan and in Rincón, a popular surfing town, actually falling into the ocean amid rising seas – and coastal flooding is getting worse.

That’s not all: The island is also challenged by intensifying tropical heat, heavier downpours and – as we just saw with Hurricane Maria – its location in the path of stronger hurricanes.

When rebuilding Puerto Rico, we need to help the island become more resilient to such impacts of climate change – while doubling down on curbing emissions that cause the problem in the first place.

Roofless homes in Puerto Rico after the storm. Photo: FEMA

Island’s economy hangs in balance

A vast majority of the Puerto Rico’s population of 3.4 million, more than 85 percent, lives within five miles of a coast that is threatened by the rising ocean.

Like islands in the South Pacific, it’s seeing sea level rise of about half a foot on average from melting land ice and warmer ocean waters. This trend, which is accelerating, has made roads, ports and other infrastructure that are key to Puerto Rico’s economy more vulnerable.

As we’ve seen over the past few weeks, sea level rise compounds the impacts of hurricanes when worsened storm surge causes flooding in communities along the coast. The resulting damage from this and other climate impacts has a direct effect on Puerto Rican daily life as well as on tourism, which accounts for 8 percent of the island’s economy.

Climate impacts are getting worse

Scientists predict Puerto Rico will see a sea level rise of 22 inches by 2060. That translates into a lot more storm surge, more destroyed property and even bigger hits to the nation’s tourist economy.

Research also suggests more heat, rainfall, and stronger hurricanes are in the future [PDF] for Puerto Rico.

The science is clear: Rising temperatures and heavier rainfall both play a key role in intensifying hurricane strength and destruction.

Ninety percent of excess heat is absorbed by the oceans and this warming water energizes hurricanes and evaporates more water into the atmosphere, increasing the amount of rainfall in storms – just like we’ve seen in recent weeks.

All these challenges will escalate in coming decades.

These fellow Americans deserve our help

As we see in Puerto Rico today, it’s the most vulnerable among us who feel the impacts of climate change the most. They need our help to build a better and stronger future.

Treating the symptoms of climate change is absolutely essential. We must come together quickly as a nation and help our fellow Americans through this crisis.

But treating the underlying disease – heat-trapping gas emissions – is equally essential. Or the devastation we’re witnessing in Puerto Rico will keep happening.

This post originally appeared on EDF Voices.

Posted in Basic Science of Global Warming, Extreme Weather, Greenhouse Gas Emissions, Health| Comments are closed

Huge Antarctic iceberg breaks off. Here's why it worries scientists.

The massive rift in the Antarctic Peninsula's Larsen C ice shelf, photographed by NASA scientists in November 2016. Photo by Stuart Rankin.

This post was co-authored by Mason Fried, a Ph.D. student of glaciology at the University of Texas Institute for Geophysics. It originally appeared on EDF Voices.

Scientists watched with alarm this week as the fourth-largest ice shelf in Antarctica rapidly broke apart, causing an enormous, Delaware-size iceberg to float into the Southern Ocean.

Scientists had been observing the anomalous rift widening across a section of the so-called Larsen C ice shelf for the past several years. Now they’re left with some critical questions: What are this event’s broader consequences for the Antarctic ice sheet, what happens next, and – importantly – what role did climate change play here?

Antarctica: A frontline for climate change

So far, scientists have been hesitant to attribute the Larsen C ice shelf breakup to rising global temperatures.

Indeed, such events – known to scientists as “calving” – occur naturally and are essential for maintaining ice shelf balance. Without them, ice shelves would grow unabated to cover large swaths of the Southern Ocean.

Still, the magnitude and timing of this ice loss warrants attention.

The Antarctic Peninsula, where the Larsen ice shelves reside, has long been viewed as a frontline for climate change. Warming in the peninsula exceeds the global average, glaciers there are retreating, and two other ice shelves on the peninsula already collapsed over the past couple of decades after being stable for thousands of years.

Such changes will help raise global sea levels by 3 to 6 feet by 2100, projections show, affecting dense coastal communities along our Eastern seaboard and across the globe.

Ice breakup starts chain reaction

We do know that this latest ice separation could set in motion a string of chain reactions that further destabilize the ice shelf and surrounding glaciers, and ultimately contribute to global sea level rise.

Ice shelves are floating extensions of grounded glaciers and ice sheets that, importantly, buttress and impede inland ice flow. When an ice shelf collapses or becomes weaker, this defense disappears, allowing inland glaciers to accelerate downslope and transport more ice to the ocean, which can quickly affect sea level.

Scientists worry that the remnant Larsen C ice shelf will now be at considerable risk of further breakup.

The new ice berg reduced the ice shelf area by more than 12 percent when it broke off, leaving behind an ice shelf that is inherently unstable. This can, in turn, trigger new ice cracks and rifting, and cause more icebergs to break off – further increasing the possibility of runaway ice loss amid rising global temperatures.

Whether or not this latest calving event will be attributed to climate change, it’s safe to say that it will make the region more vulnerable to the impacts of global warming.

Climate change caused 2002 ice shelf collapse

The Larsen C ice shelf, named for a Norwegian whaling vessel captain who sailed the Southern Sea in the late 1800s, has two smaller northern neighbors known as Larsen A and Larsen B – both of which collapsed in the past 23 years.

Those events taught us that ice sheets, landscapes we used to think of as stable and slow to change, can actually transform rapidly.

The Larsen B collapse was particularly dramatic, with nearly the entire ice shelf disintegrating during a three-week period in 2002 after remaining stable for at least 10,000 years.

The speed of that event was unprecedented and attributed directly to increasing atmospheric warming, although rising ocean temperatures and long-term ice loss from surrounding glaciers may also have played a role.

A hint of what’s to come?

After the Larsen B shelf collapse, researchers observed dramatic increases in glacier speed, thinning and ice transfer to the ocean.

Some researchers are already drawing parallels between this week’s Larsen C collapse and the series of events that led to the eventual collapse of Larsen B. The latter experienced a similar large calving event in 1995 that foreshadowed further retreat and widespread disintegration in 2002.

While it remains to be seen if and when Larsen C will meet the same fate, warning signs are already in place. What’s happening to the Larsen ice shelves could, in fact, be a proxy for what’s to come across even larger sections of the Antarctic ice sheet unless we take action to slow warming.

Posted in Arctic & Antarctic, News, Science| Comments are closed

Take these first steps to lower your impact on climate change

Happy Earth Day

The average household in the United States emits almost 100,000 pounds of carbon dioxide per year. That is about the same weight as 10 adult African elephants.

Earth Day is tomorrow, and at this time of the year, many of us are thinking about those kinds of facts. We wonder how we can personally help the climate by reducing our individual impacts.

A simple internet search will yield a laundry list of actions that may be overwhelming, and often will be far less than satisfying. You may find suggestions that are not indicative of the actual size of your impact (turning off your lights versus not flying from east to west coast, for example – they are not equivalent). You may also find information that is irrelevant to your specific lifestyle (for example, the recommendation to cut out meat when you are already a vegetarian).

Because each of our lives is unique (click here to see how carbon footprints vary by zip code), we really need to have a good understanding of our personal and professional impacts on the climate before we can determine good actions to take, and choices to make, to reduce those impacts.

Here is a table with some great resources, to help you get started:

 

PERSONALPROFESSIONAL
Calculate your carbon footprint AND determine specific actions you can take to reduce your impactUse this calculator to:

1. Determine your personal carbon footprint (broken down by travel, housing, food, goods, and services)

2. Develop your unique action plan tailored to your personal impacts (includes emissions saved, dollars saved, and upfront costs)
Use this calculator to:

1. Determine your business carbon footprint (broken down by travel, facilities, and procurement)

2. Develop your unique action plan tailored to your business impacts (includes emissions saved, dollars saved, and upfront costs)
Make better choicesLearn how to save energy and money at home, on the move, at the store, in the yard, at the curb, and at work
Learn how to be more energy efficient at home, in buildings, and in plants, and to buy more efficient products and new homes.
Posted in Cars and Pollution, Energy, Greenhouse Gas Emissions, Partners for Change, Science| Comments are closed

How Do We Know That Humans Are Causing Climate Change? These Nine Lines of Evidence

While most Americans acknowledge that climate change is happening, some are still unsure about the causes.

They are often labeled “climate skeptics,” but that label can cause confusion or even anger.

Isn’t the nature of science to be skeptical? Isn’t it good to question everything?

Yes, but —

Here’s what is getting lost in the conversation:

Scientists have been asking these questions for nearly 200 years. The scientific community has been studying these questions for so long that collectively they have amassed an overwhelming amount of evidence pointing to a clear conclusion.

A similar situation is smoking and cancer. Nowadays, no one questions the link between smoking and cancer, because the science was settled in the 1960s after more than 50 years of research. The questions have been asked and answered with indisputable evidence.

We can think of the state of human activities and climate change as no different than smoking and cancer. In fact, we are statistically more confident that humans cause climate change than that smoking causes cancer.

Our confidence comes from the culmination of over a century of research by tens of thousands of scientists at hundreds of institutions in more than a hundred nations.

So what is the evidence?

The research falls into nine independently-studied but physically-related lines of evidence, that build to the overall clear conclusion that humans are the main cause of climate change:

  1. Simple chemistry that when we burn carbon-based materials, carbon dioxide (CO2) is emitted (research beginning in 1900s)
  2. Basic accounting of what we burn, and therefore how much CO2 we emit (data collection beginning in 1970s)
  3. Measuring CO2 in the atmosphere and trapped in ice to find that it is indeed increasing and that the levels are higher than anything we've seen in hundreds of thousands of years  (measurements beginning in 1950s)
  4. Chemical analysis of the atmospheric CO2 that reveals the increase is coming from burning fossil fuels (research beginning in 1950s)
  5. Basic physics that shows us that CO2 absorbs heat (research beginning in 1820s)
  6. Monitoring climate conditions to find that recent warming of the Earth is correlated to and follows rising CO2 emissions (research beginning in 1930s)
  7. Ruling out natural factors that can influence climate like the Sun and ocean cycles (research beginning in 1830s)
  8. Employing computer models to run experiments of natural vs. human-influenced “simulated Earths” (research beginning in 1960s)
  9. Consensus among scientists that consider all previous lines of evidence and make their own conclusions (polling beginning in 1990s)

(You can also see these nine lines of evidence illustrated in the graphic below)

Skeptics sometimes point to the last two supporting lines of evidence as weaknesses. They’re not. But even if you choose to doubt them, it is really the first seven that, combined, point to human activities as the only explanation of rising global temperatures since the Industrial Revolution, and the subsequent climate changes (such as ice melt and sea level rise) that have occurred due to this global warming.

The science is settled, and the sooner we accept this, the sooner we can work together towards addressing the problems caused by climate change – and towards a better future for us all.

 

(Click here for a pdf version of the graphic)

 

Posted in Basic Science of Global Warming, Greenhouse Gas Emissions, Science, Setting the Facts Straight| Read 39 Responses
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