Articles in 2012

This study looks at solar radiation management and how the benefits will vary between regions. Using a general circulation model, the trade-offs between optimizing latitudinal and seasonal distribution of reduced solar radiation are investigated.

There is concern that species may not adapt fast enough to keep up with the changing climate. This study shows that in the past fifteen years, the hatching date of a moth species has genetically changed at a rate predicted by a model, sufficient to keep up with predicted rates of climatic change.

Shifts in evapotranspiration are investigated for non-irrigated agriculture and hydropower, and compared to irrigated agriculture and deforestation, as used predominantly in previous studies. The increase in evapotranspiration from the combined results highlights the need for models to include different human uses of water as anthropogenic drivers of hydroclimatic change.

Human impacts on the terrestrial water cycle have the potential to influence hazards such as flooding and drought, so understanding the extent of our influence is an important research goal. A study utilizing estimates of evapotranspiration for different types of land cover and a database of changes in use now shows that the extent of land-cover change caused by people is already an important factor affecting the terrestrial water cycle.

Understanding the factors that influence coral susceptibility to thermally induced bleaching may aid reef management efforts. Now corals with high symbiont cell densities are shown to be more susceptible to bleaching, indicating that environmental conditions which increase symbiont densities—such as nutrient pollution—could exacerbate climate-induced coral bleaching.

Natural sciences analyse the biophysical effects of climate change, whereas social sciences estimate their consequences for humans. How we should respond to climate change depends on how we think we should live our lives, and there are many different opinions on this matter. Ethics can bring clarity and order to these ideas.

Assessment and managment of the impacts of climate change on Earth surface systems such as glaciers, rivers and mountains are somewhat neglected in national and international climate policy initiatives. It is argued in this Perspective that this is a critical omission because Earth surface systems provide water and soil resources, sustain ecosystem services, and influence biogeochemical cycles.

The long-term demand for materials and the opportunities for scrap recycling depend on the stock dynamics of the products in use. In the case of aluminium, research shows that new technologies in primary production can reduce emissions while the aluminium stocks grow, but beyond stock saturation the largest reduction potential shifts to scrap recycling.

Indonesia accounts for a large proportion of the oil palm plantation expansion occurring globally. However, Indonesia’s mixed forests (and associated carbon stocks) complicate estimation of the contribution of oil palm agriculture to global carbon budgets. Remotely sensed land-cover classification combined with carbon flux estimates are now used to develop high-resolution estimates of carbon flux from Kalimantan plantations for the period 1990–2010.

The stimulation of plant growth by increased atmospheric CO₂ concentrations could function as a negative feedback damping the future rate of climate change. Results from a rare long-term (13 year) grassland experiment demonstrate that nitrogen supply can act to constrain the extent of CO₂ fertilization. Such interactions are not yet incorporated into Earth system models.

In the ocean, biological responses to climate change include altered distribution, phenology and productivity. A modelling study into the integrated effects of these various changes on fish body size suggests that averaged maximum body weight could fall by 14–24% globally by 2050. About half of the decline is accounted for by changes in distribution and abundance, with the remainder being physiological.

As the global climate changes, drought is expected to reduce productivity and tree survival across many forests; however, the relative influence of climate variables on forest decline remains poorly understood. A drought-stress index based on tree-ring data—newly developed for the southwestern United States—is found to be equally influenced by evaporation (primarily temperature driven) and precipitation and may serve as a holistic forest-vigour indicator in water-limited forests.