Despite the existence of institutions designed to promote peace, interactions between individuals and groups sometimes lead to conflict. Understanding the causes of such conflict is a major project in the social sciences, and researchers in anthropology, economics, geography, history, political science, psychology, and sociology have long debated the extent to which climatic changes are responsible. Recent advances and interest have prompted an explosion of quantitative studies on this question.

To meet surging domestic energy demand, provide power to the largest population in the world that lacks electricity (> 400 million people), and reduce rapidly growing CO2 emissions, the Government of India (GOI) has embarked on a fast-track dam-building program.

The role of climate change in the development and demise of Classic Maya civilization (300 to 1000 C.E.) remains controversial because of the absence of well-dated climate and archaeological sequences. We present a precisely dated subannual climate record for the past 2000 years from Yok Balum Cave, Belize. From comparison of this record with historical events compiled from well-dated stone monuments, we propose that anomalously high rainfall favored unprecedented population expansion and the proliferation of political centers between 440 and 660 C.E.

The observed presence of water vapor convectively injected deep into the stratosphere over the United States can fundamentally change the catalytic chlorine/bromine free-radical chemistry of the lower stratosphere by shifting total available inorganic chlorine into the catalytically active free-radical form, ClO. This chemical shift markedly affects total ozone loss rates and makes the catalytic system extraordinarily sensitive to convective injection into the mid-latitude lower stratosphere in summer.

The observed presence of water vapor convectively injected deep into the stratosphere over the United States fundamentally changes the catalytic chlorine/bromine free radical chemistry of the lower stratosphere by shifting total available inorganic chlorine into the catalytically active free-radical form, ClO. This chemical shift markedly affects total ozone loss rates and makes the catalytic system extraordinarily sensitive to convective injection into the mid-latitude lower stratosphere in summer.

Next week, thousands of participants from governments, the private sector, non governmental organizations, and other stakeholders will gather in Brazil at a United Nations (UN) summit to secure political and economic commitments for sustainable development and to address new and emerging challenges. These objectives recall the 1992 UN Conference on Environment and Development, also held in Rio de Janeiro. Although political progress toward these goals has stagnated, in the intervening 20 years science and technology have moved on.

Fundamental thermodynamics and climate models suggest that dry regions will become drier and wet regions will become wetter in response to warming. Efforts to detect this long-term response in sparse surface observations of rainfall and evaporation remain ambiguous. We show that ocean salinity patterns express an identifiable fingerprint of an intensifying water cycle. Our 50-year observed global surface salinity changes, combined with changes from global climate models, present robust evidence of an intensified global water cycle at a rate of 8 ± 5% per degree of surface warming.

India’s science: Excellence unrecognized. (Letters)

The Montreal Protocol is perhaps the most successful international environmental treaty, responsible for global phaseout of the consumption and production of ozone-depleting substances (ODSs), e.g., chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs). Hydrofluorocarbons (HFCs), which do not destroy stratospheric ozone, were considered long-term substitutes for ODSs and are not controlled by the Montreal Protocol. Because most HFCs are potent greenhouse gases (GHGs), they are included in the Kyoto Protocol.

At the Indian Science Congress last month, Prime Minister Manmohan Singh pledged to hike R&D expenditures from around $3 billion last year to $8 billion in 2017. The windfall is meant to turbocharge initiatives to create elite research institutions, bring expatriate Indian scientists home, enrich science education, and equip smart new laboratories. Included in this push is South Asia's first biosafety level–4 lab for handling the most dangerous pathogens, slated to be up and running this spring.