Very Hot and Very Dry Conditions Have Doubled Worldwide Posing Serious Threat to Food Systems, Study Finds

Stanford University and Charles III University   Yale Environment 360 Summary

The chance of having years that are both extremely warm and extremely dry — conditions that pose a serious threat to agricultural systems — has doubled around the globe since 1931, according to a new study published in the journal Science Advances. The research attributes this change almost entirely to human-driven climate change.

The study, conducted by scientists at Stanford University and Charles III University of Madrid, also found an uptick in dry and severely warm conditions in multiple key agricultural regions in the same year, which reduces the possibility that surpluses in one location can make up for low yields in another.

“When we look in the historical data at the key crop and pasture regions, we find that before anthropogenic climate change, there were very low odds that any two regions would experience those really severe conditions simultaneously,” Stanford climate scientist Noah Diffenbaugh, lead author of the new study, said in a statement. “The global marketplace provides a hedge against localized extremes, but we’re already seeing an erosion of that climate buffer as extremes have increased in response to global warming.”

The California drought is devastating agriculture across the state. Credit: Cerabona/Flickr

Diffenbaugh and his colleagues also found that the frequency of these simultaneous hot-dry conditions will continue to increase, by about 20 percent, over the next three decades if nations don’t drastically reduce their greenhouse gas emissions, E&E News reported.

Ali Sarhadi, María Concepción Ausín, Michael P. Wiper, Danielle Touma1 and Noah S. Diffenbaugh. Multidimensional risk in a nonstationary climate: Joint probability of increasingly severe warm and dry conditions. Science Advances  28 Nov 2018:
Vol. 4, no. 11, eaau3487 DOI: 10.1126/sciadv.aau3487


We present a framework for quantifying the spatial and temporal co-occurrence of climate stresses in a nonstationary climate. We find that, globally, anthropogenic climate forcing has doubled the joint probability of years that are both warm and dry in the same location (relative to the 1961–1990 baseline). In addition, the joint probability that key crop and pasture regions simultaneously experience severely warm conditions in conjunction with dry years has also increased, including high statistical confidence that human influence has increased the probability of previously unprecedented co-occurring combinations. Further, we find that ambitious emissions mitigation, such as that in the United Nations Paris Agreement, substantially curbs increases in the probability that extremely hot years co-occur with low precipitation simultaneously in multiple regions. Our methodology can be applied to other climate variables, providing critical insight for a number of sectors that are accustomed to deploying resources based on historical probabilities.

Climate-warming El Niño very likely in 2019, says UN agency

  • Natural cycle has major influence on global weather, bringing droughts and floods
  • There is a 75-80% chance of a climate-warming El Niño event by February, according to the latest analysis from the UN’s World Meteorological Organization.

Damian Carrington Read full GuardianUK article here

///The last El Niño event ended in 2016 and helped make that year the hottest ever recorded by adding to the heating caused by humanity’s carbon emissions. The 2019 event is not currently forecast to be as strong as in 2016.

El Niño events occur naturally every few years and stem from abnormally high ocean temperatures in the western Pacific. They have a major influence on weather around the globe, bringing droughts to normally damp places, such as parts of Australia, and floods to normally drier regions, such as in South America. The high temperatures also cause major bleaching on coral reefs.

“The forecast El Niño is not expected to be as powerful as the event in 2015-2016,” said Maxx Dilley, the director of WMO’s climate prediction and adaptation branch. “Even so, it can still significantly affect rainfall and temperature patterns in many regions, with important consequences to agriculture and food security, and for management of water resources and public health. It may also combine with long-term climate change to boost 2019 global temperatures.”…

Global warming increases the risk of an extinction domino effect

  • Co-extinctions (the disappearance of consumers following the depletion of their resources) could be a major culprit in the ongoing biodiversity crisis.
  • Global warming predictions that fail to take into account this cascading effect might underestimate extinctions by up to 10 times.

European Commission Joint Research Centre

The complex network of interdependencies between plants and animals multiplies the species at risk of extinction due to environmental change, according to a new study.

….As an obvious, direct consequence of climate change, plants and animals living in a given area are driven to extinction when the local environmental conditions become incompatible with their tolerance limits, just like fish in an aquarium with a broken thermostat. However, there are many elusive drivers of species loss that go beyond the direct effects of environmental change (and human activity) which we still struggle to understand.

In particular, it is becoming clearer that co-extinctions (the disappearance of consumers following the depletion of their resources) could be a major culprit in the ongoing biodiversity crisis….

Giovanni Strona, Corey J. A. Bradshaw. Co-extinctions annihilate planetary life during extreme environmental change. Scientific Reports, 2018; 8 (1) DOI: 10.1038/s41598-018-35068-1


A new study explores ecosystem stability. Its findings raise questions about the stability of our modern global system. See ScienceDaily summary here.

Peter D. Roopnarine, K.D. Angielczyk, A. Weik, A. Dineen. Ecological persistence, incumbency and reorganization in the Karoo Basin during the Permian-Triassic transition. Earth-Science Reviews, 2018; DOI: 10.1016/j.earscirev.2018.10.014

New federal climate assessment for U.S. released- drastic action needed to stay under 2C warming

NOAA (from ScienceDaily) and read NATURE summary here

Immediate, drastic action is needed to keep global warming under 2 °C, according to United Nations report.

A new federal report finds that climate change is affecting the natural environment, agriculture, energy production and use, land and water resources, transportation, and human health and welfare across the U.S. and its territories.

Volume II of the Fourth National Climate Assessment (NCA4), released Nov. 23, 2018 by the United States Global Change Research Program (USGCRP —, focuses on climate change impacts, risks and adaptations occurring in the U.S. The report contains supporting evidence from 16 national-level topic chapters (e.g., water, oceans, energy, and human health), 10 regional chapters and two chapters that focus on societal responses to climate change. USGCRP also released the Second State of the Carbon Cycle Report (SOCCR2 —

NOAA is one of 13 federal agencies that contributed significantly to the Fourth National Climate Assessment.

Key findings of the NCA4, Vol. II Communities

  • Human health and safety, our quality of life, and the rate of economic growth in communities across the U.S. are increasingly vulnerable to the impacts of climate change.
  • The cascading impacts of climate change threaten the natural, built and social systems we rely on, both within and beyond the nation’s borders.
  • Societal efforts to respond to climate change have expanded in the last five years, but not at the scale needed to avoid substantial damages to the economy, environment, and human health over the coming decades.
  • Without substantial and sustained global efforts to reduce greenhouse gas emissions and regional initiatives to prepare for anticipated changes, climate change is expected to cause growing losses to American infrastructure and property and impede the rate of economic growth over this century.

Agriculture and food production

  • Rising temperatures, extreme heat, drought, wildfire on rangelands and heavy downpours are expected to increasingly challenge the quality and quantity of U.S. crop yields, livestock health, price stability and rural livelihoods.


  • Continued changes to Earth’s climate will cause major disruptions in some ecosystems. Some coral reef and sea ice ecosystems are already experiencing transformational changes, affecting communities and economies that rely upon them.

Water and the coasts

  • Changes in the quality and quantity of fresh water available for people and the environment are increasing risks and costs to agriculture, energy production, industry and recreation.
  • Climate change will transform coastal regions by the latter part of this century, with ripple effects on other regions and sectors. Many communities should expect higher costs and lower property values from sea level rise.


  • Climate change threatens the health and well-being of the American people by causing increasing extreme weather, changes to air quality, the spread of new diseases by insects and pests, and changes to the availability of food and water.

To access the report and find background information, visit the USGCRP website:

Six feet under, a new approach to global warming– soil mineral carbon pathway

  • The study is the first global-scale evaluation of the role soil plays in dissolved organic carbon and the minerals that help store it.
  • Comparing different ecosystems, Kramer saw that moist environments sequestered far more carbon than dry ones. In desert climates, where rain is scarce and water easily evaporates, reactive minerals retain less than 6 percent of the soil’s organic carbon. Dry forests are not much better. But wet forests can have as much as half their total carbon bound up by reactive minerals.
  • If temperatures near the surface warm, there can be less water moving through soils even if rainfall amounts stay the same or increase.

Washington State University

A researcher has found that one-fourth of the carbon held by soil is bound to minerals as far as six feet below the surface. The discovery opens a new possibility for dealing with the element as it continues to warm the Earth’s atmosphere. One hitch: Most of that carbon is concentrated deep beneath the world’s wet forests, and they won’t sequester as much as global temperatures continue to rise.

[Scientists used] new data from soils around the world to describe how water dissolves organic carbon and takes it deep into the soil, where it is physically and chemically bound to minerals. [They] estimate that this pathway is retaining about 600 billion metric tons, or gigatons, of carbon. That’s more than twice the carbon added to the atmosphere since the dawn of the Industrial Revolution.

Scientists still need to find a way to take advantage of this finding and move some of the atmosphere’s extra carbon underground, but Kramer says the soils can easily retain more. For starters, a new understanding of the pathway is “a major breakthrough” in our understanding of how carbon goes underground and stays there, he said….

…while climate change is unlikely to directly affect the deep mineral-bound carbon, it can influence the pathway by which the carbon is buried. That is because the delivery system depends on water to leach carbon from roots, fallen leaves and other organic matter near the surface and carry it deep into the soil, where it will attach to iron- and aluminum-rich minerals eager to form strong bonds.

If temperatures near the surface warm, there can be less water moving through soils even if rainfall amounts stay the same or increase.

Marc G. Kramer, Oliver A. Chadwick. Climate-driven thresholds in reactive mineral retention of soil carbon at the global scale. Nature Climate Change, 2018; DOI: 10.1038/s41558-018-0341-4

5 Things to Know Before Next Week’s Critical UN Climate Talks

  • Next week, heads of state and representatives from roughly 200 countries will descend in Katowice, Poland for the 24th session of the Conference of the Parties to the United Nations Framework Convention on Climate Change, informally known as COP24.

Lorraine Chow  Read the full Ecowatch article here

Here are some things to know ahead of the critical summit:

1. The overarching goal. Creating a rulebook, or “work program,” on how to implement the landmark 2015 Paris agreement to limit global warming to well below 2°C by the end of the century avoid the devastating impacts of climate change

2. Calls for greater action. Unfortunately, the current commitments by world governments that signed the Paris agreement will not be enough to remain under 2°C, much less the more ambitious 1.5°C target….

3. The $100 billion question. In 2009, richer countries pledged $100 billion a year by 2020 to poorer nations to tackle the effects of climate change. Bloomberg reported that the climate funding reached $70 billion as of 2016—so there’s still a way to go…

4. What the United States will do. Preparatory meetings were held in Bangkok this past September to draft out details of the rulebook before the Katowice summit. As DeSmog explained, the U.S. was criticized over working to delay clarity over the agreement’s financing (nonetheless, a top UN negotiator praised “good progress” from the talks). Reuters reported earlier this month that President’s Trump team will “set up a side-event promoting fossil fuels” at the climate summit. Citing three sources, the American officials will “highlight the benefits of technologies that more efficiently burn fuels including coal,” Reuters reported…

5. You can participate, too. Climate change is not some far-away phenomenon, it is here now and impacts people around the globe everyday. This year, the UN created a “People’s Seat” for you to “virtually sit” and share your views alongside government leaders at the climate talks. To join the effort, tag your thoughts with hashtag #TakeYourSeat on social media.

Famed naturalist David Attenborough will deliver the “People’s Address” at the COP24 plenary on Dec. 3, which will be broadcast on social media around the world.

World’s Emissions Gap Is Widening, UN Warns: Governments must triple efforts to stay below 2C. Here’s How to Close It.

  • To stay below 1.5 C warming, governments must increase their GHG reduction efforts by 5. That means phasing out fossil fuels and increasing renewable energy.

  • Global emissions will likely need to peak by 2020 and fall 25 percent below current levels by 2030 to limit warming to below 2°C. Keeping warming to 1.5°C will require a cut of 55 percent.
  • Under current policies, however, emissions are set to keep rising through 2030. And even if all nations keep their Paris pledges, emissions are projected to be about the same in 2030 as they are today.

Emissions Gap Report- UN Environment Program

The gap between the goals of the Paris climate agreement and what countries have committed to do to achieve them is widening, a new United Nations report warns, posing a significant challenge to political leaders as they head into international climate negotiations next week.

Without a rapid reshaping of the global economy and energy systems—including ending the using of coal and ramping up renewable energy—the world is on track to sail past the temperature targets of the Paris Agreement. That could lock in centuries of dangerous warming.

Global greenhouse gas emissions rose about 1 percent last year, but the biggest change comes from dimming hopes for the rapid expansion of technology to capture carbon from the air and store it underground.

Previous UN studies had assumed carbon capture technologies would be widely deployed later in the century, allowing more leeway for global emissions. Instead, the latest Emissions Gap Report, published Tuesday, revised downward the world’s carbon budget—the total emissions allowable to stay within the targets of the Paris Agreement…..

From Nature

Whale songs’ changing pitch may be response to population, climate changes

  • There’s a seasonal variation in the whales’ pitch correlated with breaking sea ice in the southern Indian Ocean.
  • The new study rules out noise pollution as the cause of the global long-term trend, according to the study’s authors.

American Geophysical Union  Read full ScienceDaily article here

Blue whales have been dropping pitch incrementally over several decades, but the cause has remained a mystery. A new study finds a seasonal variation in the whales’ pitch correlated with breaking sea ice in the southern Indian Ocean. The new research also extends the mysterious long-term falling pitch to related baleen whales and rules out noise pollution as the cause of the global long-term trend, according to the study’s authors.

….Blue and fin whales are among the loudest animals in the oceans as well as the largest. Only males sing, humming about as loud as large ships. The whales’ loud songs can travel more than 1,000 kilometers (600 miles) underwater, allowing the whales to communicate across vast oceans.

….”We think it is something non-voluntary from the whale. Decrease the call intensity and it will decrease the call frequency, just because of the sound emission mechanism,” said Emmanuelle Leroy, lead author of the new study and a research fellow at the University of New South Wales in Australia.

The new research also uncovers a seasonal counterpoint in the calls of Antarctic blue whales, potentially related to the noise of melting sea ice. The new study finds blue whale calls in the southern Indian Ocean increase in pitch during the summer. The pitch could be increasing as whales sing louder to be heard over breaking sea ice, according to the study’s authors….

Emmanuelle C. Leroy, Jean-Yves Royer, Julien Bonnel, Flore Samaran. Long-Term and Seasonal Changes of Large Whale Call Frequency in the Southern Indian Ocean. Journal of Geophysical Research: Oceans, 2018; DOI: 10.1029/2018JC014352

Streamside forests store tons of carbon; restoration doubles carbon storage in first 10 years (new Point Blue publication)

  • Mature streamside forests store as much carbon as any other forest type in the world, helping to address climate change.
  • Planting trees to actively restore riparian forests can more than double the rate of carbon storage.
  • Carbon storage is an important and previously overlooked co-benefit of riparian forest restoration.
  • Increasing the pace and scale of riparian forest restoration is a valuable investment providing both immediate carbon sequestration value and long‐term ecosystem service benefits —including water quality, habitat for fish and wildlife, and recreational opportunities that support local economies.

by Kristen Dybala, PhD,  Read ScienceDaily coverage here

Forest restoration is a strategy for addressing climate change because forests store tons of carbon, both in the trees and the soil. However, the carbon storage potential of streamside forests is relatively unknown, despite extensive efforts to restore these forests globally. We compiled data on carbon storage from 117 publications, reports, and other data sets on streamside forests around the world to determine how they compare to other forest types and estimate how much carbon storage can be expected from restoring them.

We found that the average amount of carbon stored in mature streamside forest rivals the highest estimates for any other forest type around the world. The estimates for streamside forest vary depending on whether it is located in a relatively wet or dry, and warm or cool climate, but the average values range 168 – 390 tons of carbon per acre in the trees alone. We also found that, on average, soil carbon can be expected to more than triple when converting from an unforested site to a mature streamside forest. However, as with other forest types, it can take decades for these changes to go into full effect, on the order of 40-90 years for the carbon stored in trees (depending on climate) and more than 115 years for soil carbon. We also found that planting trees to actively restore these forests gave them a head-start: over the first 10 years, they stored carbon in the trees at more than twice the rate of forests that were regenerating naturally.

Our results reflect patterns for streamside forests around the world, but we could not find suitable data from every continent, or for actively planted streamside forests more than 50 years old. There are also other potentially important factors that we could not examine, such as the frequency of flooding. We encourage additional data collection that will allow us to further refine these estimates and better document the long-term carbon storage benefits.

Streamside ecosystems around the world have been severely degraded, and their large-scale restoration is a priority in many places, including California’s Central Valley and Brazil. Restoring these ecosystems is known to benefit water quality, habitat for fish and wildlife, and recreational opportunities like fishing and wildlife watching that help support local economies. Our results demonstrate the substantial additional benefit of carbon storage, which should increase the priority of restoring and maintaining streamside forests.

Dybala KE, Matzek V, Gardali T, Seavy NE. (2018) Carbon sequestration in riparian forests: a global synthesis and meta-analysis. Global Change Biology. 10.1111/gcb.14475.


  • Restoration of deforested and degraded landscapes is a globally recognized strategy to sequester carbon, improve ecological integrity, conserve biodiversity, and provide additional benefits to human health and well‐being. Investment in riparian forest restoration has received relatively little attention, in part due to their relatively small spatial extent. Yet, riparian forest restoration may be a particularly valuable strategy because riparian forests have the potential for rapid carbon sequestration, are hotspots of biodiversity, and provide numerous valuable ecosystem services. To inform this strategy, we conducted a global synthesis and meta‐analysis to identify general patterns of carbon stock accumulation in riparian forests. We compiled riparian biomass and soil carbon stock data from 117 publications, reports, and unpublished data sets. We then modeled the change in carbon stock as a function of vegetation age, considering effects of climate and whether or not the riparian forest had been actively planted. On average, our models predicted that the establishment of riparian forest will more than triple the baseline, unforested soil carbon stock, and that riparian forests hold on average 68–158 Mg C/ha in biomass at maturity, with the highest values in relatively warm and wet climates. We also found that actively planting riparian forest substantially jump‐starts the biomass carbon accumulation, with initial growth rates more than double those of naturally regenerating riparian forest. Our results demonstrate that carbon sequestration should be considered a strong co‐benefit of riparian restoration, and that increasing the pace and scale of riparian forest restoration may be a valuable investment providing both immediate carbon sequestration value and long‐term ecosystem service returns.

Con­ser­va­tion areas help bird­life ad­apt to cli­mate change

  • A warming climate is pushing organisms towards the circumpolar areas and mountain peaks. A recently conducted study on changes in bird populations reveals that protected areas slow down the north-bound retreat of species.

Read full Science Daily article here

…As the climate warms up, the belts of current climate conditions move further north, forcing species to follow the climate suited to them. At the same time, environmental transformation by humans is causing problems. Species are experiencing great difficulties in adapting simultaneously to a decrease in the quality of their habitat and the pressure brought on by climate change.

The study investigated changes in the abundance of bird species inside and outside conservation areas over five decades…..

…”By slowing down the harm caused by climate change, conservation areas provide us with a grace period for tackling the causes and consequences of climate change. The findings encourage us to increase the number of conservation areas, which is also what the international goal of protecting 17% of all land area does,” emphasises Aleksi Lehikoinen, an Academy research fellow at Luomus.

Conservation areas can mitigate climate change itself, since old forests and peatlands in their natural state serve as carbon sinks….

Petteri Lehikoinen, Andrea Santangeli, Kim Jaatinen, Ari Rajasärkkä, Aleksi Lehikoinen. Protected areas act as a buffer against detrimental effects of climate change-Evidence from large-scale, long-term abundance data. Global Change Biology, 2018; DOI: 10.1111/gcb.14461