Most land-based ecosystems worldwide risk ‘major transformation’ due to climate change

• Without dramatic reductions in greenhouse-gas emissions, most of the planet’s land-based ecosystems — from its forests and grasslands to the deserts and tundra — are at high risk of ‘major transformation’ due to climate change.
• “If we allow climate change to go unchecked, the vegetation of this planet is going to look completely different than it does today, and that means a huge risk to the diversity of the planet,” said Overpeck, who conceived the idea for the study with corresponding author Stephen T. Jackson of the U.S. Geological Survey.

University of Arizona new release here;  Read ScienceDaily article here

Additional new coverage:  NPR, Washington Post, The Atlantic, Courthouse News

…..The researchers used fossil records of global vegetation change that occurred during a period of post-glacial warming to project the magnitude of ecosystem transformations likely in the future under various greenhouse gas emissions scenarios.

They found that under a “business as usual” emissions scenario, in which little is done to rein in heat-trapping greenhouse-gas emissions, vegetation changes across the planet’s wild landscapes will likely be more far-reaching and disruptive than earlier studies suggested….

….”We’re talking about global landscape change that is ubiquitous and dramatic,” Overpeck said. “And we’re already starting to see it in the United States, as well as around the globe.”

…the new study, which took five years to complete, is the first to use paleoecological data — the records of past vegetation change present in ancient pollen grains and plant fossils from hundreds of sites worldwide — to project the magnitude of future ecosystem changes on a global scale….

Connor Nolan, Jonathan T. Overpeck, Judy R. M. Allen, Patricia M. Anderson, Julio L. Betancourt, Heather A. Binney, Simon Brewer, Mark B. Bush, Brian M. Chase, Rachid Cheddadi, Morteza Djamali, John Dodson, Mary E. Edwards, William D. Gosling, Simon Haberle, Sara C. Hotchkiss, Brian Huntley, Sarah J. Ivory, A. Peter Kershaw, Soo-Hyun Kim, Claudio Latorre, Michelle Leydet, Anne-Marie Lézine, Kam-Biu Liu, Yao Liu, A. V. Lozhkin, Matt S. McGlone, Robert A. Marchant, Arata Momohara, Patricio I. Moreno, Stefanie Müller, Bette L. Otto-Bliesner, Caiming Shen, Janelle Stevenson, Hikaru Takahara, Pavel E. Tarasov, John Tipton, Annie Vincens, Chengyu Weng, Qinghai Xu, Zhuo Zheng, Stephen T. Jackson. Past and future global transformation of terrestrial ecosystems under climate change. Science, 2018; 361 (6405): 920 DOI: 10.1126/science.aan5360

Deadline for climate action: Act strongly before 2035 to keep warming below 2°C

• If governments don’t act decisively by 2035 to fight climate change, humanity could cross a “point of no return” after which limiting global warming below 2°C in 2100 will be unlikely, according to a new study.
• The deadline to limit warming to 1.5°C has already passed, unless radical climate action is taken.
• Major ‘negative emissions’ could buy more time but humanity would only be able to delay the point of no return by 6 to 10 years.

European Geosciences Union  Read full ScienceDaily article here

…[Researchers] wanted to find the ‘point of no return’ or deadline for climate action: the latest possible year to start strongly cutting greenhouse-gas emissions before it’s too late to avoid dangerous climate change….

Using information from climate models, the team determined the deadline for starting climate action to keep global warming likely (with a probability of 67%) below 2°C in 2100, depending on how fast humanity can reduce emissions by using more renewable energy. Assuming we could increase the share of renewable energy by 2% every year, we would have to start doing so before 2035 (the point of no return). If we were to reduce emissions at a faster rate, by increasing the share of renewable energy by 5% each year, we would buy another 10 years.

The researchers caution, however, that even their more modest climate-action scenario is quite ambitious….

Matthias Aengenheyster, Qing Yi Feng, Frederick van der Ploeg, Henk A. Dijkstra. The point of no return for climate action: effects of climate uncertainty and risk tolerance. Earth System Dynamics, 2018; 9 (3): 1085 DOI: 10.5194/esd-9-1085-2018

Improving soil quality can slow global warming: Better land management practices can sequester enough carbon to lower global temperatures

• Well-established agricultural management practices such as planting cover crops, optimizing grazing and sowing legumes on rangelands, if instituted globally, could capture enough carbon from the atmosphere and store it in the soil to make a significant contribution to international global warming targets.
• Improved agricultural management could reduce global temperatures 0.26 degrees Celsius — nearly half a degree Fahrenheit — by 2100 when combined with aggressive carbon emission reductions — the best scenario for limiting warming from climate change.
• For the most aggressive reduction scenario, they calculated that soils would have to sequester about 0.68 petagrams of carbon per year worldwide, or 750 million U.S. tons. That is equivalent to 2.5 petagrams of carbon dioxide. One petagram is 1015 or a million billion grams.
• The researchers did not consider newer practices, such as composting, that are not studied as widely, nor did they consider the effect of improving soil on abandoned land, both of which could increase soil carbon sequestration even more. Newer climate models also could simulate how carbon uptake will change as temperatures rise and rainfall patterns change.

UC Berkeley   Read full ScienceDaily article here

….Their initial aim was to determine if such practices could reduce global temperatures at least 0.1 degree Celsius (0.18 degrees Fahrenheit). This is one-tenth of the Intergovernmental Panel on Climate Change’s goal of limiting the average global temperature increase between now and the year 2100 to 1 degree Celsius (1.8ºF), or 2″ degrees Celsius (3.6ºF)” above temperatures before the industrial revolution.

When combined with aggressive carbon emission reductions — the best scenario for limiting warming from climate change — the study found that improved agricultural management could reduce global temperatures 0.26 degrees Celsius — nearly half a degree Fahrenheit — by 2100.

….By throwing in biochar, a controversial soil additive — essentially charcoal — obtained by burning crop residue in an oxygen-free environment, these practices could offset even more warming, potentially as much as 0.46 degrees Celsius (0.7ºF).

The caveat, Silver said, is that this “is only achievable if you couple sequestration with aggressive emissions reduction.” If carbon concentrations increase in the atmosphere, then sequestration becomes less effective at reducing temperature. We would have to pull much more carbon out to realize the same reductions.

The caveat, Silver said, is that this “is only achievable if you couple sequestration with aggressive emissions reduction.” If carbon concentrations increase in the atmosphere, then sequestration becomes less effective at reducing temperature. We would have to pull much more carbon out to realize the same reductions….

…The IPCC has established carbon-reduction goals to limit average global warming in 2100 to 2 degrees Celsius (“3.6°F” ) above global average temperatures before the industrial revolution, or about 1760. Earth is already halfway to that limit, having warmed 1 degree Celsius since 1880….

….Their meta-analysis of existing studies of land management practices showed that improving soil quality could reach and even exceed this goal, largely from the improvement of degraded agricultural and grazing lands that are in use but producing less than optimally. Improved management tends to increase the biomass of crops, grass and their root systems by capturing carbon dioxide via photosynthesis, which results in more carbon storage in the soil.

“These are very commonly used approaches, though people don’t use them to sequester carbon — they are doing it for other reasons. Anytime you increase the organic content of soils, you are generally increasing the fertility, water-holding capacity, sustainability, decreasing erosion and general resilience to climate change,” said Silver, a biogeochemist who holds the Rudy Grah Endowed Chair in Forestry and Sustainability. “Sequestering carbon is a side benefit.”

….With aggressive emissions targets, improved land management could pull about 1.78 petagrams of carbon from the atmosphere each year, while adding biochar to the mix could raise the yearly sequestration rate to 2.89 petagrams….

1. Allegra Mayer, Zeke Hausfather, Andrew D. Jones, Whendee L. Silver. The potential of agricultural land management to contribute to lower global surface temperatures. Science Advances, 2018; 4 (8): eaaq0932 DOI: 1126/sciadv.aaq0932

 

Drought, groundwater loss sinks California land at alarming rate; Short-lived pause in Central California subsidence after heavy winter precipitation of 2017

• Despite much higher-than-normal amounts of rain in early 2017, drought conditions returned to the San Joaquin Valley and the ground has continued to sink.
• Using satellite-based measurements between 2012 and 2016, depletion of  Tulare Basin groundwater was estimated to be ~20x greater than the average since 1962.
• About 250 agricultural products grow there with an estimated value of $17 billion annually…. The valley holds about 75 percent of the California’s irrigated agricultural land and supplies 8 percent of the United States’ agricultural output.

Cornell University  Read full ScienceDaily article here

The San Joaquin Valley in central California, like many other regions in the western United States, faces drought and ongoing groundwater extraction, happening faster than it can be replenished. And the land is sinking as a result — by up to a half-meter annually.

Despite much higher-than-normal amounts of rain in early 2017, the large agricultural and metropolitan communities that rely on groundwater in central California experienced only a short respite from an ongoing drought. When the rain stopped, drought conditions returned and the ground has continued to sink, according to researchers.

…In the farming region of the Tulare Basin in central California, growers have been extracting groundwater for more than a century, said the researchers. Winter rains in the valley and snowmelt from the surrounding mountains replenish the groundwater annually to some extent, but drought has parched the valley since 2011.

Between 1962 and 2011, previous studies had found that the average volume of groundwater depletion each year was at least a half cubic-mile. Using satellite-based measurements between 2012 and 2016, depletion of the Tulare Basin groundwater volume was estimated at 10 miles cubed.

Fresno and Visalia border the Tulare Basin to the north, with Bakersfield to the south. About 250 agricultural products grow there with an estimated value of $17 billion annually, according to the U.S. Geological Survey. The valley holds about 75 percent of the California’s irrigated agricultural land and supplies 8 percent of the United States’ agricultural output….

Kyle D. Murray, Rowena B. Lohman. Short-lived pause in Central California subsidence after heavy winter precipitation of 2017. Science Advances, 2018; 4 (8): eaar8144 DOI: 10.1126/sciadv.aar8144

California Assembly Approves 100% Zero-Carbon Electricity by 2045; a version is already approved by State Senate and Governor expected to sign final bill

• It’s a bold move in a state that’s already seeing the devastation that comes with climate change, including heat waves, droughts, wildfires and sea level rise.

By Marianne Lavelle Read full Inside Climate News article here

In a move to solidify its role as a world leader on climate action, California would shift to 100 percent carbon-free electricity by 2045 under legislation passed Tuesday by the state Assembly.

Once the state Senate approves revisions to the bill, which it already passed once, the legislation heads to Gov. Jerry Brown for his signature. Brown hasn’t commented on it but is widely expected to sign the legislation as one of the crowning environmental achievements of his administration, which ends in January. The renewable energy commitment also comes on the cusp of a Global Climate Action Summit that Brown is hosting in San Francisco beginning Sept.12.

In a summer when California has been fighting record wildfires while facing off against the Trump administration’s attempts to rollback climate policies, the state’s Democratic-controlled legislature sought to double down on its commitment to shift away from fossil fuels….

 

Climate change more deadly, destructive & costly — CA Fourth Climate Change Assessment with recommended actions

• Read state assessment summary here with impact summaries and action recommendations.
• California’s Fourth Climate Change Assessment finds that heat waves will grow more severe and persistent, shortening the lives of thousands of Californians. Wildfires will burn more of the state’s forests. The ocean will rise higher and faster, exposing California to billions in damage along the coast….
• The state’s assessment draws on the latest science, including more than 40 new peer-reviewed studies, to project the effects of the continued rise in greenhouse gases on California’s weather, water, ecosystems and people and offer guidance on actions that can be taken
• There is an urgent need not only for swift global reductions in greenhouse gas emissions but also local actions to protect California from warming that’s already threatening people, natural resources and infrastructure.

By Tony Barboza , Bettina Boxall  and Rosanna Xia  Read full Los Angeles Times article here

Read CA 4th Climate Assessment here

….“This year has been kind of a harbinger of potential problems to come,” said Daniel Cayan, a climate researcher at the Scripps Institution of Oceanography and one of the scientists coordinating the report. “The number of extremes that we’ve seen is consistent with what model projections are pointing to, and they’re giving us an example of what we need to prepare for.”

State leaders vowed to act on the research, even as the Trump administration moves to unravel climate change regulations and allow more pollution from cars, trucks and coal-fired power plants.

“In California, facts and science still matter,” Gov. Jerry Brown said in a statement. “These findings are profoundly serious and will continue to guide us as we confront the apocalyptic threat of irreversible climate change.”…

….State energy officials said the assessment underscores the urgent need not only for swift global reductions in greenhouse gas emissions but also local actions to protect California from warming that’s already threatening people, natural resources and infrastructure.

“We’re seeing that in the fire situation, we’re seeing that in sea level rise, we’re seeing that in heat spells, in declining snowpack,” said California Energy Commission Chairman Robert Weisenmiller. “The climate is changing now so we need to be adapting our communities.”

Read the state’s assessment

 

Environmentally friendly farming practices used by nearly one third of world’s farms

• Nearly one-third of the world’s farms have adopted more environmentally friendly practices – sustainable intensification including organic farming- while continuing to be productive.
• This will help provide sufficient and nutritious food for all, while minimizing environmental impact and enabling producers to earn a decent living.
• Stronger government policies across the globe are now needed to support the greater adoption of sustainable intensification farming systems so that the United Nations Sustainable Development Goals endorsed by all members of the UN are met by 2030

Washington State University  Read full ScienceDaily article here

Nearly one-third of the world’s farms have adopted more environmentally friendly practices while continuing to be productive, according to a global assessment by 17 scientists in five countries.

The researchers analyzed farms that use some form of “sustainable intensification,” a term for various practices, including organic farming, that use land, water, biodiversity, labor, knowledge and technology to both grow crops and reduce environmental impacts like pesticide pollution, soil erosion, and greenhouse gas emissions….

The researchers focused on seven different farming changes including an Integrated Pest Management that involves Farmer Field Schools teaching farmers agroecological practices, such as building the soil, in more than 90 countries. Other changes include pasture and forage redesign, trees in agricultural systems, irrigation water management, and conservation agriculture, including the soil-saving no-till technique used in eastern Washington.

…Sustainable intensification “has been shown to increase productivity, raise system diversity, reduce farmer costs, reduce negative externalities and improve ecosystem services,” the researchers write. They say it has now reached a “tipping point” in which it can be more widely adopted through governmental incentives and policies.

“Stronger government policies across the globe are now needed to support the greater adoption of sustainable intensification farming systems so that the United Nations Sustainable Development Goals endorsed by all members of the UN are met by 2030,” said Reganold. “This will help provide sufficient and nutritious food for all, while minimizing environmental impact and enabling producers to earn a decent living.”

see here

Jules Pretty, Tim G. Benton, Zareen Pervez Bharucha, Lynn V. Dicks, Cornelia Butler Flora, H. Charles J. Godfray, Dave Goulson, Sue Hartley, Nic Lampkin, Carol Morris, Gary Pierzynski, P. V. Vara Prasad, John Reganold, Johan Rockström, Pete Smith, Peter Thorne, Steve Wratten. Global assessment of agricultural system redesign for sustainable intensification. Nature Sustainability, 2018; 1 (8): 441 DOI: 10.1038/s41893-018-0114-0

Cartoons

These cartoons are solely the opinion of the artists and may not reflect the views of Point Blue Conservation Science.

https://www.meyertoons.com/gallery.html?gallery=California%20cartoons&folio=Cartoons

https://www.cagle.com/m-e-cohen/2003/10/m-e-cohens-cartoon-for-10292003

 

https://www.meyertoons.com/gallery.html?gallery=California%20cartoons&folio=Cartoons

http://editorialcartoonists.com/cartoon/display.cfm/166340/

https://www.gocomics.com/mattdavies/2018/08/27

As CO2 levels climb, staple crops become less nutritious putting millions at risk

• Rising levels of carbon dioxide (CO₂) from human activity are making staple crops such as rice and wheat less nutritious and could result in 175 million people becoming zinc deficient and 122 million people becoming protein deficient by 2050.
• “One thing this research illustrates is a core principle of the emerging field of planetary health. We cannot disrupt most of the biophysical conditions to which we have adapted over millions of years without unanticipated impacts on our own health and well being.”

Harvard T.H. Chan School of Public Health Read full ScienceDaily article here

….The study also found that more than 1 billion women and children could lose a large amount of their dietary iron intake, putting them at increased risk of anemia and other diseases.

“Our research makes it clear that decisions we are making every day — how we heat our homes, what we eat, how we move around, what we choose to purchase — are making our food less nutritious and imperiling the health of other populations and future generations,” said Sam Myers, lead author of the study and principal research scientist at Harvard Chan School.

By the middle of this century, when atmospheric CO₂ concentrations are expected to reach around 550 ppm, 1.9% of the global population — or roughly 175 million people, based on 2050 population estimates — could become deficient in zinc and that 1.3% of the global population, or 122 million people, could become protein deficient.

Additionally, 1.4 billion women of childbearing age and children under 5 who are currently at high risk of iron deficiency could have their dietary iron intakes reduced by 4% or more.

…”One thing this research illustrates is a core principle of the emerging field of planetary health,” said Myers, who directs the Planetary Health Alliance, co-housed at Harvard Chan School and Harvard University Center for the Environment. “We cannot disrupt most of the biophysical conditions to which we have adapted over millions of years without unanticipated impacts on our own health and wellbeing.”

Matthew R. Smith, Samuel S. Myers. Impact of anthropogenic CO2 emissions on global human nutrition. Nature Climate Change, 2018; DOI: 10.1038/s41558-018-0253-3

Wildfire risk doesn’t douse housing demand

• New study found that real estate prices for homes in wildfire-prone areas fall immediately following a blaze but sale prices in risky areas rebound within one to two years.
• Residential growth in forested areas across the United States — areas of landscape commonly referred to as the Wildland-Urban Interface (WUI) — significantly increased in recent years from an estimated 30.8 million housing units in 1990 to 43.4 million by 2010.

Read full ScienceDaily article here

That’s the conclusion of a new UNLV study which found that real estate prices for homes in wildfire-prone areas fall relative to homes in low-risk areas immediately following a blaze. But the effect is only temporary: Sale prices in risky areas rebound within one to two years.

While that may sound like a blessing to homeowners and real estate agents alike, UNLV research economist Shawn McCoy says the phenomenon may also pose somewhat of a curse.

That’s because homebuyers place such a significant premium on homes with the appealing views and beautifully isolating dense vegetation provided by mountainous high-fire risk areas that even media coverage of out-of-control blazes, mass evacuations, or deaths may not deter them. As a result, residential growth in forested areas across the United States — areas of landscape commonly referred to as the Wildland-Urban Interface (WUI) — significantly increased in recent years from an estimated 30.8 million housing units in 1990 to 43.4 million by 2010….

“Despite an initial drop in real estate prices in risk-prone areas, the results of our study suggest that homebuyers’ initial fears about fire risk will fade, and development in risk areas may continue to increase,” he said. “This is a problem: A lot of recent work shows that wildfires are not just a result of changes in global climates, but also rapid housing development into forested lands.”…

Shawn J. McCoy, Randall P. Walsh. Wildfire risk, salience & housing demand. Journal of Environmental Economics and Management, 2018; DOI: 10.1016/j.jeem.2018.07.005