Climate 411

What you need to know about hurricanes and climate change

Photo: NOAA

This post was co-authored by EDF Postdoctoral Climate Science Fellow Tianyi Sun

Today Hurricane Laura made landfall in Louisiana as a Category 4 hurricane, causing death and destruction. Louisianans and Texans in its path are now mourning and looking ahead to a long and painful recovery.

Laura had winds up to 150 miles per hour, making it one of the strongest hurricanes on record to ever hit the Gulf Coast in the United States. It tied the record for how quickly it intensified, driving questions about the role of climate change in creating and fueling this monster storm.

A look at the latest science

Scientists have been actively studying how climate change affects hurricanes for decades, and the evidence that it can influence several aspects of hurricanes continues to grow.

Overall, climate change is making these already dangerous weather events even more perilous. They are stronger, wetter, slower, and intensify more rapidly. Major storms are occurring more often and piling on heavier rainfall, and scientists anticipate the strongest storms will continue to increase in frequency. Sea level rise, along with stronger winds, are also worsening storm surges, causing more coastal flooding.

All aspects of hurricanes – from formation to track to strength to damages – can be influenced to some degree by climate change, through warmer waters, more moisture in the atmosphere, changing air patterns, and sea level rise.

For some connections, such as how climate change affects hurricane strength and its damages, the science is simple and robust. For other connections, such as how climate change affects hurricane formation and track, the science is more complicated and nuanced.

Here we break down what we know about how climate change affects four key aspects of hurricanes


1. Hurricane formation – competing factors at play
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Posted in Basic Science of Global Warming, Extreme Weather, News, Oceans, Science / Comments are closed

Hansen was right: Marking an anniversary by misleading the public

Dr. James Hansen testifying before Congress in 1988

With the thirtieth anniversary of former NASA scientist Jim Hansen’s landmark testimony to Congress on the urgent need to address climate change, numerous articles marked the occasion by demonstrating that his 1988 predictions have proven to be accurate.

Inevitably, some writers seized the opportunity to revive long-debunked arguments in an attempt to cast doubt and confusion on the threat.

Perhaps the most misleading – and certainly the highest profile – was a June 21st op-ed in the Wall Street Journal written by Pat Michaels and Ryan Maue. Michaels is director of the Center for the Study of Science at the Cato Institute, a think tank financially linked to the fossil fuel industry. And Michaels has been found to have previously misled Congress by presenting a doctored graph of Hansen’s projections during public testimony before the House Small Business Committee.

Four decades of climate model projections have fared well

Their latest effort implies that U.S. climate policy is based on Hansen’s forecasts in 1988, and therefore we must “reconsider environmental policy” according to an evaluation of “how well his forecasts have done.”

In reality, climate policy is based on hundreds of years of collective research and an overwhelming amount of observational evidence gathered from all over the world.

Climate model development began as early as the 1950s, and projections from 1973 to 2013 (including Hansen’s 1988 paper) have been compared to observed temperatures by multiple institutions. All showed reasonably accurate surface temperature increases between 1970 and 2016, Hansen’s 1988 study included.

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Posted in Basic Science of Global Warming, Greenhouse Gas Emissions, News, Science, Setting the Facts Straight / Comments are closed

Natural disasters are no longer purely natural

You may have heard the alarming news that weather and climate disasters in the U.S. killed 362 people in 2017 and caused a record $306 billion in damages.

But also alarming is the fact that many news outlets are still referring to these events as “natural disasters.”

Southeast Texas after Hurricane Harvey – a not-purely-natural disaster. Photo: U.S. Department of Defense

With recent advances in science, researchers have found that human-caused climate change plays a major role in making certain events occur and/or making them worse. That means that many “natural disasters” are no longer purely “natural.”

Here is a look at some not-so-natural disasters:

  • Hurricane Harvey 2017: human-caused climate change made record rainfall over Houston around three times more likely and 15 percent more intense
  • European Extreme Heat 2017: human-caused climate change made intensity and frequency of such extreme heat at least 10 times as likely in Portugal and Spain
  • Australian Extreme Heat 2017: maximum summer temperatures like those seen during 2016-2017 are now at least 10 times more likely with human-caused climate change
  • Louisiana Downpours 2016: human-caused climate change made events like this 40 percent more likely and increased rainfall intensity by around 10 percent
  • European Rainstorms 2016: human-caused climate change made probability of three-day extreme rainfall this season at least 40 percent more likely in France
  • UK Storm Desmond 2015: human-caused climate change made extreme regional rainfall roughly 60 percent more likely
  • Argentinian Heat Wave 2013/2014: human-caused climate change made the event around five times more likely

By employing the term “natural disasters,” news outlets and others are inadvertently implying that all of these events are just misfortunate incidences – rather than consequences of our actions.

This seemingly innocuous phrase supports the idea that dangerous weather is out of our control.

But, we do have some control over their frequency and intensity, and that control is through our emissions of heat-trapping gases.

We need to act on climate, and we need to do it now. Pointing out that we worsen and may even cause these weather disasters may help convince people to do what needs to be done.

Posted in Basic Science of Global Warming, Extreme Weather, News, Science, Setting the Facts Straight / Read 1 Response

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