Global Climate Observing System

Learning from the authors of the IPCC Fourth Assessment Report and its findings to help guide future strategies for climate change observations and research was the key objective of a workshop organised jointly by the Global Climate Observing System (GCOS), the World Climate Research Programme (WCRP), and the International Geosphere-Biosphere Programme (IGBP) in Sydney, Australia, 4-6 October 2007

On the Variability of Southern Ocean Front Locations Between Southern Brazil and the Antarctic Peninsula

A 4-year expendable bathythermograph data set (1984–1987) from the area between southern Brazil and the Antarctic Peninsula provides information on the interannual variability of front locations. Two boundaries of subtropical water at different depths are identified north and south of the Brazil Current-Falkland (Malvinas) Current confluence zone. The northern Subtropical Front is displaced over a large part of the Argentine Basin from one observational period to the other. The shallow southern Subtropical Front appears fixed to the Falkland Escarpment. The Polar Front and Subantarctic Front locations do not vary much, except for one case where a cold core eddy in the Polar Frontal Zone causes a large northward displacement of the Subantarctic Front

Aerosol forcing in the Climate Model Intercomparison Project (CMIP5) simulations by HadGEM2-ES and the role of ammonium nitrate

The latest Hadley Centre climate model, HadGEM2-ES, includes Earth system components such as interactive chemistry and eight species of tropospheric aerosols. It has been run for the period 1860–2100 in support of the fifth phase of the Climate Model Intercomparison Project (CMIP5). Anthropogenic aerosol emissions peak between 1980 and 2020, resulting in a present-day all-sky top of the atmosphere aerosol forcing of −1.6 and −1.4 W m−2 with and without ammonium nitrate aerosols, respectively, for the sum of direct and first indirect aerosol forcings. Aerosol forcing becomes significantly weaker in the 21st century, being weaker than −0.5 W m−2 in 2100 without nitrate. However, nitrate aerosols become the dominant species in Europe and Asia and decelerate the decrease in global mean aerosol forcing. Considering nitrate aerosols makes aerosol radiative forcing 2–4 times stronger by 2100 depending on the representative concentration pathway, although this impact is lessened when changes in the oxidation properties of the atmosphere are accounted for. Anthropogenic aerosol residence times increase in the future in spite of increased precipitation, as cloud cover and aerosol-cloud interactions decrease in tropical and midlatitude regions. Deposition of fossil fuel black carbon onto snow and ice surfaces peaks during the 20th century in the Arctic and Europe but keeps increasing in the Himalayas until the middle of the 21st century. Results presented here confirm the importance of aerosols in influencing the Earth's climate, albeit with a reduced impact in the future, and suggest that nitrate aerosols will partially replace sulphate aerosols to become an important anthropogenic species in the remainder of the 21st century

Just transitions for a Climate-Resilient Development in Africa – Transforming Dialogue into Action

CCDA-X1, hosted by the Government of Namibia, convened on the theme: “Just transitions for a Climate-Resilient Development in Africa – Transforming Dialogue into Action” in collaboration with Africa’s civil society organisations, academia, development partners, regional and international organisations and the private sector. The conference resulted in the following key messages to be taken forward to COP27 by Namibia

Assessment of Social Vulnerability to Natural Hazards in the Mountain Kingdom of Lesotho

Lesotho's landlocked mountainous setting with thin regolith cover and poor economic situation make it vulnerable to hazardous events associated with climate such as drought, floods, strong winds, heavy snowfall, and severe frost. To date, no quantitatively based vulnerability assessment has been undertaken in this heavily populated, developing region in southern Africa. The primary aim of this study was to assess social vulnerability of communities to natural hazards by applying a place-based social vulnerability index developed for the United States, to the Lesotho context. The study used 2006 Lesotho census data, district government records, and household interviews to identify 27 indicators of social vulnerability in southern Lesotho, and then used principal components analysis to generate a social vulnerability index for the study region. Index scores were summed and then mapped to quantify spatial variability in social vulnerability. The study results show a clustering of highly vulnerable communities in the rural highlands as a result of underdevelopment, poverty, and inaccessibility

Ravaged landscapes and climate vulnerability: The challenge in achieving food security and nutrition in post-conflict Timor-Leste

Food insecurity and malnutrition are prevalent in post-conflict countries. Climate change poses further challenges to their food production. Timor-Leste is an agrarian society that won independence in 2002 and is struggling to achieve food security and reduce undernutrition as the country modernizes. The economy depends on fossil fuel revenues and oil reserves are dwindling. A review of climate, agricultural, and nutrition data reveals high weather vulnerability, low agricultural productivity, and slow dietary and nutritional progress. But solutions exist. Agricultural sector actions can make important contributions to poverty reduction, food security, dietary diversity, micronutrient sufficiency, and overall nutrition. Agriculture can be made to be more nutrition- and gender-sensitive with a focus on mixed farming systems, biodiversity, climate-smart practices, and access to inputs, training, and technologies for farmers to enable sustainable and healthy rural livelihoods. Ultimately, productivity levels must improve to support the availability of sufficient and nutritious foods