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Volcanic Eruption Affects Sea Level Rise

A new study in the journal Scientific Reports suggests that the evidence to pinpoint expected acceleration of sea-level rise due to climate change was hiding behind the effects of a 1991 eruption of Mount Pinatubo. This eruption sent tens of millions of tons of sulphur dioxide into the stratosphere and may have masked the effects of industrial pollution on global sea levels during the two decades since.

“What we’ve shown is that sea level acceleration is real, and it continues to be going on, it’s ongoing, and we understand why you don’t see it in the short satellite record,” said John Fasullo, who conducted the research along with scientists from the University of Colorado in Boulder and Old Dominion University. The data from satellite observations that scientists have used to track sea-level rise began in 1993, two years after the eruption, which temporarily cooled the planet. These data indicated that the rate of sea-level rise was holding fairly steady at about 3 millimeters per year.

“When we used climate model runs designed to remove the effect of the Pinatubo eruption, we saw the rate of sea level rise accelerating in our simulations,” Fasullo said. “Now that the impacts of Pinatubo have faded, this acceleration should become evident in the satellite measurements in the coming decade, barring another major volcanic eruption.”

Climate Change Extending Mosquito Season, Raising Zika Risk

A portion of last week’s opening Olympic ceremonies in Rio de Janeiro focused squarely on climate change. A video offered a glimpse of climate change effects and an accompanying graphic showing the incursion of sea-level rise on cities around the world if the average global temperature were to increase 3–4 degrees. Fitting perhaps, suggested The Washington Post, given warming could help accelerate outbreaks of mosquito-borne illnesses such as Zika, which has spread from Brazil to Florida, leading to serious birth defects.

Although data confirming a formal link between climate change and the rise and spread of the virus are lacking, Climate Central reports that the initial Brazilian outbreak of Zika was “aided by a drought driven by El Niño, and by higher temperatures caused by longer-term weather cycles and by rising levels of greenhouse gas pollution.” Climate Central’s own research recently showed that in three quarters of major U.S. cities warming temperatures have lengthened the mosquito season—the number of days hot and humid enough for mosquitoes to be biting. According to that research, the ten cities with the biggest increase in the length of the mosquito season over the last 30 years were Baltimore, Maryland; Durham, North Carolina; Minneapolis, Minnesota; Myrtle Beach, South Carolina; Raleigh, North Carolina; Portland, Maine; St. Louis, Missouri; Pittsburgh, Pennsylvania; Worcester, Massachusetts; and Albany, New York.

For Rio, Zika is not the only health risk potentially increased by longer, rainy summers.

Ratifying the Paris Agreement

In Paris last year, more than 190 countries pledged to hold the global average temperature increase to “well below” 2 degrees Celsius above pre-industrial levels and to pursue efforts to limit that increase to 1.5 degrees Celsius. But keeping within that 1.5 degree Celsius target, The Guardian reports, will be extremely difficult.

An analysis by the Ministry of Foreign Affairs of the Republic of the Marshall Islands—the third country to ratify the Paris Agreement—suggests that the agreement is nearing a critical threshold of pledges and is likely to enter into force this year or in early 2017. The agreement takes effect 30 days after at least 55 countries representing at least 55 percent of the world’s greenhouse gas emissions ratify it. The Marshall Islands analysis indicates 58 countries together representing nearly 54 percent of global emissions have either ratified or pledged to work toward ratification of the Paris Agreement by the end of the year.

So far, 22 nations accounting for 1.08 percent of emissions have formally ratified the deal, according to the United Nations.

The Climate Post offers a rundown of the week in climate and energy news. It is produced each Thursday by Duke University’s Nicholas Institute for Environmental Policy Solutions.