Constraining Amazonian land surface temperature sensitivity to precipitation and the probability of forest dieback

Chai, Yuanfang; Martins, Guilherme; Nobre, Carlos A.; Randow, Celso von; Chen, Tiexi; Dolman, A. J.

doi:10.1038/s41612-021-00162-1

Cited by 31 publications

(28 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Researchers forecast a possibility of doubling of the burned area south of the Brazilian Amazon in the coming decades [43]. This projection is in accordance with the scenarios proposed by the Intergovernmental Panel on Climate Change, which are based on global numerical models [44] that indicate increased environmental degradation in the near future. Indeed, the Amazon ecosystem has been identified as a region with the highest vulnerability index in ecosystem function, particularly in areas of large-scale forest degradation and fragmentation [45].…”

Section: Introductionsupporting

confidence: 75%

Fires Drive Long-Term Environmental Degradation in the Amazon Basin

et al. 2022

View full text Add to dashboard Cite

The Amazon Basin is undergoing extensive environmental degradation as a result of deforestation and the rising occurrence of fires. The degradation caused by fires is exacerbated by the occurrence of anomalously dry periods in the Amazon Basin. The objectives of this study were: (i) to quantify the extent of areas that burned between 2001 and 2019 and relate them to extreme drought events in a 20-year time series; (ii) to identify the proportion of countries comprising the Amazon Basin in which environmental degradation was strongly observed, relating the spatial patterns of fires; and (iii) examine the Amazon Basin carbon balance following the occurrence of fires. To this end, the following variables were evaluated by remote sensing between 2001 and 2019: gross primary production, standardized precipitation index, burned areas, fire foci, and carbon emissions. During the examined period, fires affected 23.78% of the total Amazon Basin. Brazil had the largest affected area (220,087 fire foci, 773,360 km2 burned area, 54.7% of the total burned in the Amazon Basin), followed by Bolivia (102,499 fire foci, 571,250 km2 burned area, 40.4%). Overall, these fires have not only affected forests in agricultural frontier areas (76.91%), but also those in indigenous lands (17.16%) and conservation units (5.93%), which are recognized as biodiversity conservation areas. During the study period, the forest absorbed 1,092,037 Mg of C, but emitted 2908 Tg of C, which is 2.66-fold greater than the C absorbed, thereby compromising the role of the forest in acting as a C sink. Our findings show that environmental degradation caused by fires is related to the occurrence of dry periods in the Amazon Basin.

show abstract

Section: Introductionsupporting

confidence: 75%

Fires Drive Long-Term Environmental Degradation in the Amazon Basin

et al. 2022

View full text Add to dashboard Cite

show abstract

“…We suspect that a possible reason for this uncertainty is the large SED in the Amazon region that is due to the large values of most climate indicators (Δ T , Δ P , Δ T var , Δ P var and Δ Dry ), resulting in large order‐of‐magnitude differences among the CMIP models. On the other hand, the current results show that the CMIP models generally perform poorly in simulating Amazonian temperature and precipitation, a problem that arises from the models' diverse sea surface temperature responses and soil moisture feedbacks and generates considerable uncertainty in model projections (Chai et al., 2021; Joetzjer et al., 2013). Central and western Africa, which is a persistent hotspot identified by the CMIP6 models, always shows smaller magnitudes of inter‐model uncertainty relative to other hotspot regions of the globe.…”

Section: Resultsmentioning

confidence: 81%

Future Climate Change Hotspots Under Different 21st Century Warming Scenarios

et al. 2021

View full text Add to dashboard Cite

Identifying climate change hotspot regions is critical for planning effective mitigation and adaptation activities. We use standard Euclidean distance (SED) to calculate integrated changes in precipitation and temperature means, interannual variability, and extremes between different future warming levels and a baseline period (1995–2014) using the Coupled Model Intercomparison Project Phase 6 (CMIP6) climate model ensemble. We find consistent hotspots in the Amazon, central and western Africa, Indonesia and the Tibetan Plateau at warming levels of 1.5°C, 2°C, and 3°C for all scenarios explored; the Arctic, Central America and southern Africa emerge as hotspots at 4°C warming and at the end of the 21st century under two Shared Socioeconomic Pathways scenarios, SSP3‐7.0 and SSP5‐8.5. CMIP6 models show higher SED values than CMIP5, suggesting stronger aggregated effects of climate change under the new scenarios. Hotspot time of emergence (TOE) is further investigated; TOE is defined as the year when the climate change signal first exceeds the noise of natural variability in 21st century projections. The results indicate that TOEs for warming would occur over all primary hotspots, with the earliest occurring in the Arctic and Indonesia. For precipitation, TOEs occur before 2100 in the Arctic, the Tibetan Plateau and Central America. Results using a geographical detector model show that patterns of SED are shaped by extreme hot and dry occurrences at low‐to‐medium warming, while precipitation and temperature means and extreme precipitation occurrences are the dominant influences under the high emission scenario and at high warming levels.

show abstract

“…We used Eq. ( 5 ) to estimate the PDF of the original projected variable (from CMIP6) before applying the emergent constraint 25 , 28 . where PDF( y / x ) is the PDF around the best-fit linear regression, representing the PDF of y given x .…”

Section: Methodsmentioning

confidence: 99%

“…Recently, an innovative technique called the emergent constraint has been developed to constrain uncertainty across climate model ensemble projections 24 – 28 . The uncertainty in model simulations can be constrained by observations to obtain more accurate projections of future climate change 29 by developing physically explainable empirical relationships between the simulated current and future climate.…”

Section: Introductionmentioning

confidence: 99%

Constrained CMIP6 projections indicate less warming and a slower increase in water availability across Asia

et al. 2022

Self Cite

View full text Add to dashboard Cite

Climate projections are essential for decision-making but contain non-negligible uncertainty. To reduce projection uncertainty over Asia, where half the world’s population resides, we develop emergent constraint relationships between simulated temperature (1970–2014) and precipitation (2015–2100) growth rates using 27 CMIP6 models under four Shared Socioeconomic Pathways. Here we show that, with uncertainty successfully narrowed by 12.1–31.0%, constrained future precipitation growth rates are 0.39 ± 0.18 mm year−1 (29.36 mm °C−1, SSP126), 0.70 ± 0.22 mm year−1 (20.03 mm °C−1, SSP245), 1.10 ± 0.33 mm year−1 (17.96 mm °C−1, SSP370) and 1.42 ± 0.35 mm year−1 (17.28 mm °C−1, SSP585), indicating overestimates of 6.0–14.0% by the raw CMIP6 models. Accordingly, future temperature and total evaporation growth rates are also overestimated by 3.4–11.6% and −2.1–13.0%, respectively. The slower warming implies a lower snow cover loss rate by 10.5–40.2%. Overall, we find the projected increase in future water availability is overestimated by CMIP6 over Asia.

show abstract

Constraining Amazonian land surface temperature sensitivity to precipitation and the probability of forest dieback

Cited by 31 publications

References 47 publications

Fires Drive Long-Term Environmental Degradation in the Amazon Basin

Fires Drive Long-Term Environmental Degradation in the Amazon Basin

Future Climate Change Hotspots Under Different 21st Century Warming Scenarios

Constrained CMIP6 projections indicate less warming and a slower increase in water availability across Asia

Contact Info

Product

Resources

About