Proxy-based indicators of past climate change show that current global climate models systematically underestimate Holocene-epoch climate variability on centennial to multi-millennial timescales, with the mismatch increasing for longer periods. Proposed explanations for the discrepancy include ocean–atmosphere coupling that is too weak in models, insufficient energy cascades from smaller to larger spatial and temporal scales, or that global climate models do not consider slow climate feedbacks related to the carbon cycle or interactions between ice sheets and climate.

The waters of the Southern Ocean have absorbed much of the excess heat and carbon generated by humanity.

Original Source

With prices for renewables dropping, many countries in Africa might leap past dirty forms of energy towards a cleaner future.

Original Source

Two South American metropolises are enlisting bacterium-infected mosquitoes to fight Zika. The effort is the world’s biggest test yet of an unconventional but promising approach to quell mosquito-borne diseases.

Original Source

Analysis of observations and model projections provides large-scale emergent constraints on the extent of CO2 fertilization, with estimated increases in gross primary productivity for both high-latitude and extratropical ecosystems under elevated atmospheric CO2 concentrations.

The emergence of HIV-1 group M subtype B in North American men who have sex with men was a key turning point in the HIV/AIDS pandemic. Phylogenetic studies have suggested cryptic subtype B circulation in the United States (US) throughout the 1970s and an even older presence in the Caribbean. However, these temporal and geographical inferences, based upon partial HIV-1 genomes that postdate the recognition of AIDS in 1981, remain contentious and the earliest movements of the virus within the US are unknown.

A study clarifies when HIV entered the United States and dispels the myth that one man instigated the AIDS epidemic in North America.

The world’s rivers deliver 19 billion tonnes of sediment to the coastal zone annually1, with a considerable fraction being sequestered in large deltas, home to over 500 million people. Most (more than 70 per cent) large deltas are under threat from a combination of rising sea levels, ground surface subsidence and anthropogenic sediment trapping2, 3, and a sustainable supply of fluvial sediment is therefore critical to prevent deltas being ‘drowned’ by rising relative sea levels2, 3, 4.

Reconstructions of Earth’s past climate strongly influence our understanding of the dynamics and sensitivity of the climate system. Yet global temperature has been reconstructed for only a few isolated windows of time, and continuous reconstructions across glacial cycles remain elusive. Here I present a spatially weighted proxy reconstruction of global temperature over the past 2 million years estimated from a multi-proxy database of over 20,000 sea surface temperature point reconstructions.

Here we report the Simons Genome Diversity Project data set: high quality genomes from 300 individuals from 142 diverse populations. These genomes include at least 5.8 million base pairs that are not present in the human reference genome. Our analysis reveals key features of the landscape of human genome variation, including that the rate of accumulation of mutations has accelerated by about 5% in non-Africans compared to Africans since divergence.