The Unpredictable Critical Threshold in COVID-19 Pandemic and Climate Change

AbstractTemperature sensitivity—the magnitude of a biological response per °C—is a fundamental concept across scientific disciplines, especially biology, where temperature determines the rate of many plant, animal and ecosystem processes. Recently, a growing body of literature in global change biology has found temperature sensitivities decline as temperatures rise (Fuet al., 2015; Güsewell et al., 2017; Piao et al., 2017; Chen et al., 2019; Dai et al., 2019). Such observations have been used to suggest climate change is reshaping biological processes, with major implications for forecasts of future change. Here we present a simple alternative explanation for observed declining sensitivities: the use of linear models to estimate non-linear temperature responses. We show how linear estimates of sensitivities will appear to decline with warming for events that occur after a cumulative thermal threshold is met—a common model for many biological events. Corrections for the non-linearity of temperature response in simulated data and long-term phenological data from Europe remove the apparent decline. Our results show that rising temperatures combined with linear estimates based on calendar time produce observations of declining sensitivity—without any shift in the underlying biology. Current methods may thus undermine efforts to identify when and how warming will reshape biological processes.Significance statementRecently a growing body of literature has observed declining temperature sensitivities of plant leafout and other events with higher temperatures. Such results suggest that climate change is already reshaping fundamental biological processes. These temperature sensitivities are often estimated as the magnitude of a biological response per °C from linear regression. The underlying model for many events—that a critical threshold of warmth must be reached to trigger the event—however, is non-linear. We show that this mismatch between the statistical and biological models can produce the illusion of declining sensitivities with warming using current methods. We suggest simple alternative approaches that can better identify when and how warming will reshape biological processes.

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Ice Season forecast under ClimateChange: Tipping element approach

10.5194/egusphere-egu2020-20073 ◽

2020 ◽

Author(s):

Elena Surovyatkina ◽

Roman Medvedev

Keyword(s):

Climate Change ◽

Sea Ice ◽

Sea Of Okhotsk ◽

Surface Air Temperature ◽

Critical Threshold ◽

Data Set ◽

Near Surface ◽

The Sea Of Okhotsk ◽

Starting Point ◽

Element Approach

The Sea of Okhotsk is a marginal sea of the western Pacific Ocean. It is one of the world's richest in biological resources and famous for the fishing industry. In winter, navigation on the Sea is difficult, if not impossible, due to the harsh conditions of the North and the presence of sea ice. On average, the ice-free period lasts from June to November. However, the start and end dates of the ice season vary from year to year within a month. Such variability is impossible to capture by meteorological methods, which have a limit of predictability for 10 days. The absence of a long-term forecast of the navigational period in the Sea of Okhotsk affects the safety of navigation and the reliability of transit transport.Most of the studies of the distribution of ice floes focus on such factors as the location, time of year, water currents, and sea temperatures. In our study, we use the distribution of temperature in the atmosphere and wind direction (NCEP/NCAR re-analyses data set) because most of the area of the Sea of Okhotsk is located in monsoon climate zone. We propose a new approach to forecast predicting the upcoming ice advance/ retreat date by developing our Tipping element approach [1] elaborated for prediction of the Indian Summer Monsoon, which proved to be successful for prediction upcoming monsoon four years in a row (2016-2019).The physical mechanism underlying forecast is the following. There is an atmospheric feature that appears at the beginning of the transition to the ice season. We show, for the first time, the evidence in observational data that a transition from open water season to ice season begins when the near-surface air temperature crosses a critical threshold. It appears in the form of spatially organized critical transitions in the atmosphere over the see. This event happening 2-3 months before the ice season is a starting point forecasting date of ice advance. We perform forecast in critical areas - tipping elements of the spatial structure of ice formation, which we identified via data analysis.The retrospective test (over the period 2001-2017) confirms that the methodology allows forecasting the ice advance/retreat date more than one month in advance, with a success rate in 88% of the years within the error of +/- 4 days. Forecasts of the upcoming season 2018-2019 show successful results as well.Climate change affects the ice season in the Sea of Okhotsk in the following aspects: there has been a declining trend in sea ice cover in recent years due to delays in the ice advance date. Season shift because it takes for the atmosphere longer time cooling down in autumn. The novel approach allows for accounting climate change effects.ES acknowledges financial support of the&#160;EPICC project (18_II_149_Global_A_Risikovorhersage) funded by BMU, RM acknowledges the Russian Foundation for Basic Research (RFBR) (No. 20-07-01071)[1] Stolbova, V., E. Surovyatkina, B. Bookhagen, and J. Kurths (2016): Tipping elements of the Indian monsoon: Prediction of onset and withdrawal. GRL 43, 1&#8211;9 [doi:10.1002/2016GL068392]

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Threshold or Limit? Precipitation Dependency of Austrian Landslides, an Ongoing Challenge for Hazard Mapping under Climate Change

Sustainability ◽

10.3390/su12156182 ◽

2020 ◽

Vol 12 (15) ◽

pp. 6182

Author(s):

Ivo Offenthaler ◽

Astrid Felderer ◽

Herbert Formayer ◽

Natalie Glas ◽

David Leidinger ◽

...

Keyword(s):

Climate Change ◽

Forest Cover ◽

Spatial Information ◽

Critical Threshold ◽

Hazard Mapping ◽

Small Scale ◽

Observation Data ◽

Earth Observation Data ◽

Rain Events ◽

Observation Bias

Climate change is set to increase landslide frequency around the globe, thus increasing the potential exposure of people and material assets to these disturbances. Landslide hazard is commonly modelled from terrain and precipitation parameters, assuming that shorter, more intense rain events require less precipitation volume to trigger a slide. Given the extent of non-catastrophic slides, an operable vulnerability mapping requires high spatial resolution. We combined heterogeneous regional slide inventories with long-term meteorological records and small-scale spatial information for hazard modelling. Slope, its (protective) interaction with forest cover, and altitude were the most influential terrain parameters. A widely used exponential threshold to estimate critical precipitation was found to incorrectly predict meteorological hazard to a substantial degree and, qualitatively, delineate the upper boundary of natural conditions rather than a critical threshold. Scaling rainfall parameters from absolute values into local probabilities (per km²) however revealed a consistent pattern across datasets, with the transition from normal to critical rain volumes and durations being gradual rather than abrupt thresholds. Scaled values could be reverted into site-specific nomograms for easy appraisal of critical rain conditions by local stakeholders. An overlay of terrain-related hazard with infrastructure yielded local vulnerability maps, which were verified with actual slide occurrence. Multiple potential for observation bias in ground-based slide reporting underlined the value of complementary earth observation data for slide mapping and early warning.

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Abrupt Circulation Responses to Tropical Upper-Tropospheric Warming in a Relatively Simple Stratosphere-Resolving AGCM

Journal of Climate ◽

10.1175/jcli-d-11-00166.1 ◽

2012 ◽

Vol 25 (12) ◽

pp. 4097-4115 ◽

Cited By ~ 17

Author(s):

Shuguang Wang ◽

Edwin P. Gerber ◽

Lorenzo M. Polvani

Keyword(s):

Climate Change ◽

General Circulation ◽

Climate Models ◽

Climate Model ◽

Polar Vortex ◽

Circulation Model ◽

Hadley Cell ◽

Critical Threshold ◽

Intergovernmental Panel ◽

Upper Troposphere

Abstract The circulation response of the atmosphere to climate change–like thermal forcing is explored with a relatively simple, stratosphere-resolving general circulation model. The model is forced with highly idealized physics, but integrates the primitive equations at resolution comparable to comprehensive climate models. An imposed forcing mimics the warming induced by greenhouse gasses in the low-latitude upper troposphere. The forcing amplitude is progressively increased over a range comparable in magnitude to the warming projected by Intergovernmental Panel on Climate Change coupled climate model scenarios. For weak to moderate warming, the circulation response is remarkably similar to that found in comprehensive models: the Hadley cell widens and weakens, the tropospheric midlatitude jets shift poleward, and the Brewer–Dobson circulation (BDC) increases. However, when the warming of the tropical upper troposphere exceeds a critical threshold, ~5 K, an abrupt change of the atmospheric circulation is observed. In the troposphere the extratropical eddy-driven jet jumps poleward nearly 10°. In the stratosphere the polar vortex intensifies and the BDC weakens as the intraseasonal coupling between the troposphere and the stratosphere shuts down. The key result of this study is that an abrupt climate transition can be effected by changes in atmospheric dynamics alone, without need for the strong nonlinearities typically associated with physical parameterizations. It is verified that the abrupt climate shift reported here is not an artifact of the model’s resolution or numerics.

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Water restrictions under climate change: a Rhône–Mediterranean perspective combining bottom-up and top-down approaches

Hydrology and Earth System Sciences ◽

10.5194/hess-23-3683-2019 ◽

2019 ◽

Vol 23 (9) ◽

pp. 3683-3710 ◽

Cited By ~ 7

Author(s):

Eric Sauquet ◽

Bastien Richard ◽

Alexandre Devers ◽

Christel Prudhomme

Keyword(s):

Climate Change ◽

Decision Making ◽

Rapid Assessment ◽

Low Flow ◽

Critical Threshold ◽

Climate Conditions ◽

Wide Range ◽

Management Plans ◽

Water Restrictions ◽

And Performance

Abstract. Drought management plans (DMPs) require an overview of future climate conditions for ensuring long-term relevance of existing decision-making processes. To that end, impact studies are expected to best reproduce decision-making needs linked with catchment intrinsic sensitivity to climate change. The objective of this study is to apply a risk-based approach through sensitivity, exposure and performance assessments to identify where and when, due to climate change, access to surface water constrained by legally binding water restrictions (WRs) may question agricultural activities. After inspection of legally binding WRs from the DMPs in the Rhône–Mediterranean (RM) district, a framework to derive WR durations was developed based on harmonized low-flow indicators. Whilst the framework could not perfectly reproduce all WR ordered by state services, as deviations from sociopolitical factors could not be included, it enabled the identification of most WRs under the current baseline and the quantification of the sensitivity of WR duration to a wide range of perturbed climates for 106 catchments. Four classes of responses were found across the RM district. The information provided by the national system of compensation to farmers during the 2011 drought was used to define a critical threshold of acceptable WR that is related to the current activities over the RM district. The study finally concluded that catchments in mountainous areas, highly sensitive to temperature changes, are also the most predisposed to future restrictions under projected climate changes considering current DMPs, whilst catchments around the Mediterranean Sea were found to be mainly sensitive to precipitation changes and irrigation use was less vulnerable to projected climatic changes. The tools developed enable a rapid assessment of the effectiveness of current DMPs under climate change and can be used to prioritize review of the plans for those most vulnerable basins.

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Pronounced loss of Amazon rainforest resilience since the early 2000s

10.21203/rs.3.rs-379902/v1 ◽

2021 ◽

Author(s):

Chris Boulton ◽

Timothy Lenton ◽

Niklas Boers

Keyword(s):

Climate Change ◽

Land Use ◽

Land Use Change ◽

Regional Climate ◽

Global Scale ◽

Dry Season ◽

Amazon Rainforest ◽

Critical Threshold ◽

Broadleaf Tree ◽

Tree Coverage

Abstract The resilience of the Amazon rainforest to climate and land-use change is of critical importance for biodiversity, regional climate, and the global carbon cycle. Some models project future climate-driven Amazon rainforest dieback and transition to savanna1. Deforestation and climate change, via increasing dry-season length2,3 and drought frequency – with three 1-in-100-year droughts since 20054-6 – may already have pushed the Amazon close to a critical threshold of rainforest dieback7,8. However, others argue that CO2 fertilization should make the forest more resilient9,10. Here we quantify Amazon resilience by applying established indicators11 to remotely-sensed vegetation data with focus on vegetation optical depth (1991-2016), which correlates well with broadleaf tree coverage. We find that the Amazon rainforest has been losing resilience since 2003, consistent with the approach to a critical transition. Resilience is being lost faster in regions with less rainfall, and in parts of the rainforest that are closer to human activity. Given observed increases in dry-season length2,3 and drought frequency4-6, and expanding areas of land use change, loss of resilience is likely to continue. We provide direct empirical evidence that the Amazon rainforest is losing stability, risking dieback with profound implications for biodiversity, carbon storage and climate change at a global scale.

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Water restrictions under climate change: a Rhone-Mediterranean perspective combining ‘bottom up’ and ‘top- down’ approaches

10.5194/hess-2018-456 ◽

2018 ◽

Author(s):

Eric Sauquet ◽

Bastien Richard ◽

Alexandre Devers ◽

Christel Prudhomme

Keyword(s):

Climate Change ◽

Decision Making ◽

Rapid Assessment ◽

Future Climate ◽

Low Flow ◽

Critical Threshold ◽

Climate Projections ◽

Climate Conditions ◽

Wide Range ◽

Water Restrictions

Abstract. Drought management plans (DMPs) require an overview of future climate conditions for ensuring long term relevance of existing decision-making processes. To that end, impact studies are expected to best reproduce decision-making needs linked with catchment intrinsic sensitivity to climate change. The objective of this study is to apply a risk-based approach through sensitivity, exposure and sustainability assessments to evaluate the vulnerability of current DMPs operating in the Rhône-Méditerranée (RM) district to future climate projections. After inspection of legally-binding water restrictions (WR) from the DMPs in the RM district, a framework to derive WR durations was developed based on harmonized low-flow indicators. Whilst the framework could not perfectly reproduce all WR ordered by state services, as deviations from socio-political factors could not be included, it enabled to identify most WRs under current baseline, and to quantify the sensitivity of WR duration to a wide range of perturbed climates for 106 catchments. Four classes of responses were found across the RM district. Using the drought of 2011 to define a critical threshold of acceptable WR, the analysis showed that catchments in mountainous areas, highly sensitive to temperature changes, are also the most predisposed to future restrictions under projected climate changes considering current DMPs whilst catchments around the Mediterranean Sea, mainly sensitive to precipitation changes, were less vulnerable to projected climatic changes. The tools developed enable a rapid assessment of the effectiveness of current DMPs under climate change, and can be used to prioritize review of the plans for those most vulnerable basins.

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Averting robo-bees: why free-flying robotic bees are a bad idea

Emerging Topics in Life Sciences ◽

10.1042/etls20190063 ◽

2019 ◽

Vol 3 (6) ◽

pp. 723-729

Author(s):

Roslyn Gleadow ◽

Jim Hanan ◽

Alan Dorin

Keyword(s):

Climate Change ◽

Computer Simulation ◽

Food Security ◽

European Countries ◽

Plant Interactions ◽

Plant Insect Interactions ◽

Native Habitat ◽

Insect Pollinators ◽

Insect Interactions

Food security and the sustainability of native ecosystems depends on plant-insect interactions in countless ways. Recently reported rapid and immense declines in insect numbers due to climate change, the use of pesticides and herbicides, the introduction of agricultural monocultures, and the destruction of insect native habitat, are all potential contributors to this grave situation. Some researchers are working towards a future where natural insect pollinators might be replaced with free-flying robotic bees, an ecologically problematic proposal. We argue instead that creating environments that are friendly to bees and exploring the use of other species for pollination and bio-control, particularly in non-European countries, are more ecologically sound approaches. The computer simulation of insect-plant interactions is a far more measured application of technology that may assist in managing, or averting, ‘Insect Armageddon' from both practical and ethical viewpoints.

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Modelling ecosystem adaptation and dangerous rates of global warming

Emerging Topics in Life Sciences ◽

10.1042/etls20180113 ◽

2019 ◽

Vol 3 (2) ◽

pp. 221-231 ◽

Cited By ~ 4

Author(s):

Rebecca Millington ◽

Peter M. Cox ◽

Jonathan R. Moore ◽

Gabriel Yvon-Durocher

Keyword(s):

Climate Change ◽

Global Warming ◽

Diffusion Rate ◽

Individual Species ◽

Genetic Evolution ◽

Rates Of Change ◽

Rapid Climate Change ◽

Warming Climate ◽

Intraspecies Competition ◽

High Trait

Abstract We are in a period of relatively rapid climate change. This poses challenges for individual species and threatens the ecosystem services that humanity relies upon. Temperature is a key stressor. In a warming climate, individual organisms may be able to shift their thermal optima through phenotypic plasticity. However, such plasticity is unlikely to be sufficient over the coming centuries. Resilience to warming will also depend on how fast the distribution of traits that define a species can adapt through other methods, in particular through redistribution of the abundance of variants within the population and through genetic evolution. In this paper, we use a simple theoretical ‘trait diffusion’ model to explore how the resilience of a given species to climate change depends on the initial trait diversity (biodiversity), the trait diffusion rate (mutation rate), and the lifetime of the organism. We estimate theoretical dangerous rates of continuous global warming that would exceed the ability of a species to adapt through trait diffusion, and therefore lead to a collapse in the overall productivity of the species. As the rate of adaptation through intraspecies competition and genetic evolution decreases with species lifetime, we find critical rates of change that also depend fundamentally on lifetime. Dangerous rates of warming vary from 1°C per lifetime (at low trait diffusion rate) to 8°C per lifetime (at high trait diffusion rate). We conclude that rapid climate change is liable to favour short-lived organisms (e.g. microbes) rather than longer-lived organisms (e.g. trees).

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Climate change and breeding success: decline of the capercaillie in Scotland

Journal of Animal Ecology ◽

10.1046/j.1365-2656.2001.00473.x ◽

2001 ◽

Vol 70 (1) ◽

pp. 47-61 ◽

Cited By ~ 86

Author(s):

Robert Moss ◽

James Oswald ◽

David Baines

Keyword(s):

Climate Change ◽

Breeding Success

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