Climate and southern Africa's water-energy-food nexus

In southern Africa, the connections between climate and the water-energy-food nexus are strong. Physical and socioeconomic exposure to climate is high in many areas and in crucial economic sectors. Spatial interdependence is also high, driven for example, by the regional extent of many climate anomalies and river basins and aquifers that span national boundaries. There is now strong evidence of the effects of individual climate anomalies, but associations between national rainfall and Gross Domestic Product and crop production remain relatively weak. The majority of climate models project decreases in annual precipitation for southern Africa, typically by as much as 20% by the 2080s. Impact models suggest these changes would propagate into reduced water availability and crop yields. Recognition of spatial and sectoral interdependencies should inform policies, institutions and investments for enhancing water, energy and food security. Three key political and economic instruments could be strengthened for this purpose; the Southern African Development Community, the Southern African Power Pool, and trade of agricultural products amounting to significant transfers of embedded water

The U.S. National Climate Change Assessment: Do the Climate Models Project a Useful Picture of Regional Climate?

9 pages. Includes illustrations Dr. Roger A. Pielke, Sr., President of the American Association of State Climatologists, Colorado State Climatologist and Professor, Department of Atmospheric Science, Colorado State University From testimony presented to the House Subcommittee on Oversight and Investigations, July 25, 2002, and published in Colorado Water, April 2003, 15-19

The U.S. National Climate Change Assessment: Do the Climate Models Project a Useful Picture of Regional Climate?

9 pages. Includes illustrations Dr. Roger A. Pielke, Sr., President of the American Association of State Climatologists, Colorado State Climatologist and Professor, Department of Atmospheric Science, Colorado State University From testimony presented to the House Subcommittee on Oversight and Investigations, July 25, 2002, and published in Colorado Water, April 2003, 15-19

The local impacts of climate change in the Ferlo, Western Sahel

Recent increases in the accuracy of climate models have enhanced the possibilities for analyzing the impacts of climate change on society. This paper explores how the local, economic impacts of climate change can be modeled for a specific eco-region, the Western Sahel. The people in the Sahel are highly dependent on their natural resource base, and these resources are highly vulnerable to climate change, in particular to changes in rainfall. Climate models project substantial changes in rainfall in the Sahel in the coming 50 years, with most models predicting a reduction in rainfall. To connect climate change to changes in ecosystem productivity and local income, we construct an ecological¿economic model that incorporates rangeland dynamics, grazing and livestock prices. The model shows that decreased rainfall in the Sahel will considerably reduce local incomes, in particular if combined with increases in rainfall variability. Adaptation to these climate change projections is possible if reductions in rainfall are followed by destocking to reach efficient grazing levels. However, while such a strategy is optimal from the perspective of society, the stocking rate is determined by individual pastoralists that face few incentives to destoc

Global Security, Climate Change, and the Arctic

This issue of Swords and Ploughshares examines the complex set of global security challenges that are emerging as a result of warmer temperatures and melting ice in the Arctic region. For policymakers and analysts alike, the contemporary Arctic presents a particularly acute convergence of compelling problems and opportunities related to global security, foreign affairs, climate change, environmentalism, international law, energy economics, and the rights of indigenous populations. The goals of this publication are two-fold: to provide thoughtful analysis of recent developments in the Arctic both from scientific and geopolitical perspectives; and to offer careful and informed assessments of how evolving conditions in the Arctic might impact the broader global security framework and relations between the international actors involved, not to mention the region’s inhabitants and ecosystem. The articles in this issue were contributed by each of four panelists invited by the Program in Arms Control, Disarmament, and International Security (ACDIS), the European Union Center, and the Russian, East European, and Eurasian Center at the University of Illinois to participate in a November 2009 symposium entitled “Global Security, Climate Change, and the Arctic: Implications of an Open Northwest Passage.” The symposium and this publication were supported through grants to the host centers from the European Commission, the US Department of Education (Title VI international education program), and the John D. and Catherine T. MacArthur Foundation.published or submitted for publicationnot peer reviewe

Climate Models Underestimate the Sensitivity of Arctic Sea Ice to Carbon Emissions

Arctic sea ice has steadily diminished as atmospheric greenhouse gas concentrations have increased. Using observed data from 1979 to 2019, we estimate a close contemporaneous linear relationship between Arctic sea ice area and cumulative carbon dioxide emissions. For comparison, we provide analogous regression estimates using simulated data from global climate models (drawn from the CMIP5 and CMIP6 model comparison exercises). The carbon sensitivity of Arctic sea ice area is considerably stronger in the observed data than in the climate models. Thus, for a given future emissions path, an ice-free Arctic is likely to occur much earlier than the climate models project. Furthermore, little progress has been made in recent global climate modeling (from CMIP5 to CMIP6) to more accurately match the observed carbon-climate response of Arctic sea ice

Brief communication. Drought likelihood for East Africa

The East Africa drought in autumn of year 2016 caused malnutrition, illness and death. Close to 16 million people across Somalia, Ethiopia and Kenya needed food, water and medical assistance. Many factors influence drought stress and response. However, inevitably the following question is asked: are elevated greenhouse gas concentrations altering extreme rainfall deficit frequency? We investigate this with general circulation models (GCMs). After GCM bias correction to match the climatological mean of the CHIRPS data-based rainfall product, climate models project small decreases in probability of drought with the same (or worse) severity as 2016 ASO (August to October) East African event. This is by the end of the 21st century compared to the probabilities for present day. However, when further adjusting the climatological variability of GCMs to also match CHIRPS data, by additionally bias-correcting for variance, then the probability of drought occurrence will increase slightly over the same period

The Arctic-Subarctic sea ice system is entering a seasonal regime: Implications for future Arctic amplification

The loss of Arctic sea ice is a conspicuous example of climate change. Climate models project ice-free conditions during summer this century under realistic emission scenarios, reflecting the increase in seasonality in ice cover. To quantify the increased seasonality in the Arctic-Subarctic sea ice system, we define a non-dimensional seasonality number for sea ice extent, area, and volume from satellite data and realistic coupled climate models. We show that the Arctic-Subarctic, i.e. The northern hemisphere, sea ice now exhibits similar levels of seasonality to the Antarctic, which is in a seasonal regime without significant change since satellite observations began in 1979. Realistic climate models suggest that this transition to the seasonal regime is being accompanied by a maximum in Arctic amplification, which is the faster warming of Arctic latitudes compared to the global mean, in the 2010s. The strong link points to a peak in sea-ice-related feedbacks that occurs long before the Arctic becomes ice-free in summer

Lessons from the unusual impacts of an abnormal winter in the USA

Economic impacts from the near record warm and snow-free winter of 2001–2 in the United States were assessed to ascertain their dimensions and relevance to issues like climate prediction and climate change. Unusual impacts resulted and embraced numerous sectors (heating/energy use, construction, tourism, insurance, government, and retail sales). Many outcomes were gains/benefits totalling $19.6 billion, with losses of$8.2 billion. Some economists identified the sizable positive impacts as a factor in the nation’s recovery from an on-going recession stemming from the terrorist attacks on 11 September 2001. Understanding the impacts of such a winter reveals how climate predictions of such conditions could have great utility in minimising the losses and maximising the gains. The results also have relevance to the global warming issue since most climate models project future average winter temperature and snowfall conditions in the United States to be similar to those experienced in 2001–2