With this post we begin a new series of blogs that will seek to keep us up to date on the science of climate change and actions to reduce and adapt to the impacts. We will search out the latest research studies by climate scientists as well as new reports and initiatives by those who propose new ways of understanding, communicating, and dealing with global warming. This being 350 Pensacola, we will put special emphasis on research and actions relating to coastal cities. But our reach will be broad as all inhabitants of the Earth, no matter where on this planet they live, are being affected increasingly by the rise in temperatures and the impacts of a warming world. –Larry Chamblin
Paris climate agreement offers hope
With the historic agreement reached at the Paris climate summit last December, we have new hope that the nations of the world are at least taking a first step toward the reductions of greenhouse gases essential to a sustainable future. Yet scientists estimate that the emission caps agreed to in Paris will only reduce emissions by about half as much as needed to avoid a 2 degree Celsius (3.6 degree Fahrenheit) or higher increase in global temperatures.
“The deal alone won’t dig us out of the hole that we’re in, but it makes the sides less steep.” –Kumi Naidoo, executive director of Greenpeace International, summing up the Paris climate agreement in the Guardian.
In short succession we have seen two developments that create new uncertainties about the Clean Power Plan and possibly the Paris climate agreement: a Supreme Court decision to suspend the plan pending resolution of law suits against it by 27 states, including Florida; and the death of Supreme Court justice Antonin Scalia, who voted for the temporary stay of the emissions plan.
The Supreme Court’s decision to halt, for now, the Clean Power Plan is likely to remove the September deadline for states to begin submitting their plans for meeting the emission reductions. Some observers say the court’s order will likely delay the plan’s implementation by at least a year.
The Clean Power Plan is widely viewed as key to the ability of the US to meet its Paris agreement to cut emissions 26 to 28 percent below 2005 levels by 2025. All of this underlines the importance of electing a president who will support the emissions plan. At 350 Pensacola’s February 9 meeting, we took a look at how the presidential candidates view climate change, a view that highlights the division between the parties on the issue.
“Large wildfires are happening more frequently and burning more area across the western U.S. in part due to rising temperatures. The global average temperature is shown between the flames and the forest.” –Jill Pelto, a painter based in Maine
Hotter and hotter is the new norm
The combination of a strong El Nino and continuing rise in greenhouse gas emissions is likely to produce another record year in 2016. So we have had two record-breaking years in a row, and the top 10 hottest years have happened since 1998.
Kevin Trenberth, of the Climate Analysis Section at the USA National Center for Atmospheric Research, says today’s record heat is becoming the new norm.
As one example, on a recent February day, the temperature in Pensacola reached 75 degrees compared with the average high for the date of 62 degrees.
Climate change deniers continue to talk of the pause in warming, but Skeptical Science explains that “the overall heating of the planet never paused or even slowed down. The warming of surface temperatures did briefly slow, due to a period with more La Niña than El Niño events since the turn of the century. However, with the apparent return of more El Niño events, global surface temperatures are surging, and it’s hard to even see the slowdown anymore.” Skeptical Science also rejects the claim of deniers that satellite data show a warming slowdown, explaining that the data does not refute the record warming occurring at the Earth’s surface.
But are we to blame?
Are these record-warm years and weather extremes the result of human activity, or could they just be part of the natural climate cycle? Several recent studies, using a variety of methodologies, have concluded that the warming trend, as well as such weather extremes as heavy downpours and droughts, are far more likely to occur because of human activities—primarily fossil fuel burning and deforestation—that intensify the naturally occurring weather.
Michael Mann, of Penn State, and other scientists set out to answer the question of the likelihood of recent warmth occurring without human forcing. Their results are reported in Scientific Reports journal: “…the recent record temperature years are roughly 600 to 130,000 times more likely to have occurred under conditions of anthropogenic than in its absence. Our findings thus underscore the profound impact that anthropogenic forcing has already had on temperature extremes.”
A University of Oxford study of the widespread floods in southern England in 2013-14 concluded that the extreme rainfall that produced the flooding and caused more than $600 million in damages “was made 43% more likely by human-induced climate change.” One researcher said that climate change is likely to make such “once-in-a century” events much more common.
Finally, a University of Birmingham (UK) study has concluded that the extreme drought that devastated agriculture in California is clearly linked to climate change.
Cities face threats but also have opportunities
Cities will bear the brunt of some of these effects, but cities also have opportunities for reducing emissions and saving money in doing so, according to recent studies.
Coastal cities like Pensacola are more vulnerable to flooding
Coastal cities are even more vulnerable to flooding than previously thought, according to a study by Columbia University and several other universities and research organizations. The study emphasizes the compounding effects of sea level rise and stronger storms. Sea level rise itself, of course, is caused by the thermal expansion brought on by rising ocean temperatures and by the flow of water into the oceans from melting sea ice.
The heavy downpour that caused Pensacola’s historic flooding in April 2014 is an example of how extreme storms combine with higher seas to produce historic floods. The National Oceanic and Atmospheric Administration, one of the participating agencies in the National Climate Assessment, predicts that storm intensity will increase by 2 – 11 percent by 2100 and that hurricanes will produce 10 – 15 percent more rain.
The new study found that sea level rise and stronger storms produce a synergy that will cause a 4 – 75-fold increase in the flood index—the combination of flood height and duration.
“If we continue to combust fossil fuels with no restraints, the flood index could increase by a factor of 350. And this wouldn’t only occur in some distant land but also in U.S. cities like Atlantic City, New Jersey, and Pensacola, Florida.” — Natural Resources Defense Council
Speaking of heavy downpours and flooding, scientists predict that most of the US—including NW Florida—can expect more heavy rains in future decades. Climate Central has this graph showing the upward trend from 1950 to 2014, which makes visual what residents of Pensacola and other areas have experienced in recent years.
World’s Cities Face Growing Water Challenges
The becalmed mariner in Samuel Taylor Coleridge’s “Rime of the Ancient Mariner” bemoans his fate with these lines: “Water, water, every where,/ Nor any drop to drink.”
Increasingly, according to a new report, cities will find themselves in a similar situation. A new report on cities, Urban Water Blueprint, finds that “one in four of the world’s largest cities, representing more than 800 million people, are currently water stressed and many more face scarcity in terms of water quality.” Causes include urban population growth, degradation of watersheds from agriculture and increasing use of fertilizers, and the growing impacts of climate change.
Conducted by the Nature Conservancy in conjunction with C40 and the International Water Association, the study determined that the biggest gains in water quality and availability for cities would come from improved agricultural practices and forest protection, such as fencing off cattle and purchase of easements. The report concludes that “investment in natural infrastructure to preserve drinking watersheds is both an economically viable and environmentally sound approach available to developed and developing cities alike.” A quarter of all cities would realize a positive return on these investments.
Water shortages affect two-thirds of world population
Two-thirds of the world population—about 4 billion people, half of them in China and India—experience severe water shortages at least one month each year, according to a study by a university in the Netherlands. Water shortage areas include areas of South Florida and Texas.
Water shortages occur when households, industries and farms consume twice the amount of water normally available in the area, thus causing declines in groundwater levels and reduced river and lake water.
Big emission cuts could save cities trillions
Speaking of cities, the New Climate Economy has issued another report—“Accelerating Low-Carbon Development in the World’s Cities”—that highlights the savings cities could achieve by making buildings more efficient, investing in public transportation and big increases in the use of high-efficiency lighting. The report estimates the potential savings at $17 trillion by 2050.
The report says “cycling has multiple benefits for cities,” including reduced costs for health care and infrastructure (compared to motorized vehicle infrastructure).
Transportation is a key issue determining the livability, economy, and sustainability of cities. The International Sustainability Institute has produced a wonderful graphic that presents an image of the various ways of transporting 200 people. Too often, these people are riding in 177 cars (mostly with the driver alone) that clog the streets. But just look how open the streets are when the same people ride a bus or their bicycle. And just imagine the savings cities could realize if they had more and better bike lanes and public transportation and fewer streets dominated by automobiles and SUVs.