Crop-climate feedbacks boost U.S. maize and soy yields

U.S. maize and soy production have increased rapidly since the mid-20th century. While global warming has raised temperatures in most regions over this time period, trends in extreme heat have been smaller over U.S. croplands, reducing crop-damaging high temperatures and benefiting maize and soy yields. Here we show that agricultural intensification has created a crop-climate feedback in which increased crop production cools local climate, further raising crop yields. We find that maize and soy production trends have driven cooling effects approximately as large as greenhouse gas induced warming trends in extreme heat over the central U.S. and substantially reduce them over the southern U.S., benefiting crops in all regions. This reduced warming has boosted maize and soy yields by 3.3 (2.7 – 3.9; 13.7 – 20.0%) and 0.6 (0.4 – 0.7; 7.5 – 13.7%) bu/ac/decade, respectively, between 1981 and 2019. Our results suggest that if maize and soy production growth were to stagnate, the ability of the crop-climate feedback to mask warming would fade, exposing U.S. crops to more harmful heat extremes.

Will population exposure to heat extremes intensify over Southeast Asia in a warmer world?

Temperature extremes have increased during the past several decades and are expected to intensify under current rapid global warming over Southeast Asia (SEA). Exposure to rising temperatures in highly vulnerable regions affects populations, ecosystems, and other elements that may suffer potential losses. Here, we evaluate changes in temperature extremes and future population exposure over SEA at global warming levels (GWLs) of 2.0 °C and 3.0 °C using outputs from the Coupled Model Intercomparison Project Phase 6 (CMIP6). Results indicate that temperature extreme indices are projected to increase over SEA at both GWLs, with more significant magnitudes at 3.0 °C. However, daily temperature ranges (DTR) show a decrease. The substantial increase in total SEA population exposure to heat extremes from 730 million person-days at 2.0 °C GWL to 1,200 million person-days at 3.0 °C GWL is mostly contributed by the climate change component, accounting for 48%. In addition, if the global warming is restricted well below 2.0 °C, the avoided impacts in population exposure are prominent for most regions over SEA with the largest mitigation in the Philippines (PH). Aggregate population exposure to impacts is decreased by approximately 39% at 2.0 °C GWL, while the interaction component effect, which is associated with increased population and climate change, would decrease by 53%. This indicates the serious consequences for growing populations concurrent with global warming impacts if the current fossil-fueled development pathway is adhered to. The present study estimates the risks of increased temperature extremes and population exposure in a warmer future, and further emphasizes the necessity and urgency of implementing climate adaptation and mitigation strategies in SEA.

Drivers behind the summer 2010 wave train leading to Russian heatwave and Pakistan flooding

Summer 2010 saw two simultaneous extremes linked by an atmospheric wave train: a record-breaking heatwave in Russia and severe floods in Pakistan. Here, we study this wave event using a large ensemble climate model experiment. First, we show that the circulation in 2010 reflected a recurrent wave train connecting the heatwave and flooding events. Second, we show that the occurrence of the wave train is favored by three drivers: (1) 2010 sea surface temperature anomalies increase the probability of this wave train by a factor 2-to-4 relative to the model’s climatology, (2) early-summer soil moisture deficit in Russia not only increases the probability of local heatwaves, but also enhances rainfall extremes over Pakistan by forcing an atmospheric wave response, and (3) high-latitude land warming favors wave-train occurrence and therefore rainfall and heat extremes. These findings highlight the complexity and synergistic interactions between different drivers, reconciling some seemingly contradictory results from previous studies.

A Review of Corrosion Resistance Alloy Weld Overlay Cladding Material for Geothermal Applications

Geothermal is known as renewable energy and a clean energy source but inherent properties make this energy clean. Minerals and deposits in geothermal reservoirs create a scale that is persistent in its corrosive nature. In addition, heat extremes and pressure variations present challenges to the integrity of the wellhead components and the downhole casing. Such challenges need to be mitigated to achieve maximum output from these aging or even newly commissioned wells. The geothermal power industry has reported a wide range of corrosion problems. Given the highly corrosive conditions to be treated in the geothermal sector and the benefits of reduced unplanned downtime, operating cost savings would be expected if more CRAs clad products were used. In many cases, only the material's surface requires corrosion resistance and carbon or alloy steel can be clad with a more corrosion-resistant alloy. Up to 80% of the cost of using solid alloy can be saved by cladding. Carbon or low-alloy steel cladding can be carried out by overlay welding. This paper reviews available literature on corrosion in the geothermal environment and presents the successful use of clad products in other industries to support the rising demand for Philippine geothermal applications.

Increasing heat and rainfall extremes now far outside the historical climate

Over the last decade, the world warmed by 0.25 °C, in-line with the roughly linear trend since the 1970s. Here we present updated analyses showing that this seemingly small shift has led to the emergence of heat extremes that would be virtually impossible without anthropogenic global warming. Also, record rainfall extremes have continued to increase worldwide and, on average, 1 in 4 rainfall records in the last decade can be attributed to climate change. Tropical regions, comprised of vulnerable countries that typically contributed least to anthropogenic climate change, continue to see the strongest increase in extremes.

Characteristics of Heatwaves in Africa: Morocco 2000 and South Africa 2015/16

Heatwaves pose an ever increasing risk to African communities as exposure to heat extremes can have a drastic effect on individuals and in some cases can even result in death. This study presents new information about the characteristics of historical African heatwaves including a comprehensive synopsis of documented heatwave events from 1980 until 2020.Detailed research on heatwave case studies helps to inform the development of early warning systems and forecasting, which is an urgent priority. Here, the focus is on two reported heatwaves, Morocco 2000 and South Africa 2015/16. Both heatwaves feature in the Emergency Events Disaster database (EM-DAT) and include reported impacts, with the Morocco heat being the only hazard to be associated with an economic cost. In addition, these heatwaves reveal how the mechanisms behind them are closely influenced by synoptic systems and geography of their regions. Further, It is demonstrated there is some reporting by African Nations for heatwaves but that this needs significant improvement.

The effect of forced change and unforced variability in heat waves, temperature extremes, and associated population risk in a CO₂-warmed world

This study investigates the impact of global warming on heat and humidity extremes by analyzing 6 h output from 28 members of the Max Planck Institute Grand Ensemble driven by forcing from a 1 % yr−1 CO2 increase. We find that unforced variability drives large changes in regional exposure to extremes in different ensemble members, and these variations are mostly associated with El Niño–Southern Oscillation (ENSO) variability. However, while the unforced variability in the climate can alter the occurrence of extremes regionally, variability within the ensemble decreases significantly as one looks at larger regions or at a global population perspective. This means that, for metrics of extreme heat and humidity analyzed here, forced variability in the climate is more important than the unforced variability at global scales. Lastly, we found that most heat wave metrics will increase significantly between 1.5 and 2.0 ∘C, and that low gross domestic product (GDP) regions show significantly higher risks of facing extreme heat events compared to high GDP regions. Considering the limited economic adaptability of the population to heat extremes, this reinforces the idea that the most severe impacts of climate change may fall mostly on those least capable of adapting.

Weather index insurance will offset heat-induced rice loss under global warming

Global warming threatens food security through causing increasing and severe yield losses from heat extremes, especially for smallholder rice-cropping farmers in Asia. Weather index insurance (WII) could transfer weather-related risks, secure farms’ income, and recover agricultural systems. Under future warming scenarios, however, the related studies are still scarce. Here, compared with the historical period (1961-2010), heat-induced loss will approximately increase by up to 5%, 18%, and 26% at 2100 under three shared socioeconomic pathways of CMIP6, respectively. As an ex-ante strategy, county-specific WII will improve farmers’ income by up to 13% and stabilize it by up to 36%, even though the pure premium rate of WII will increase by 10% at 2050 and by 30% at 2100. For the first time, our study proves WII is one effective adaptation strategy for the most susceptible farmers under global warming and has the potential to be applied for other crops and countries.

Rapidly Increasing Chance of Record-Shattering Heat Extremes

A new study warns that we need to expect and prepare for unprecedented heat waves in the near future.