Ephemeral stream water contributions to United States drainage networks.

Ephemeral streams flow only in direct response to precipitation and are ubiquitous landscape features. However, little is known about their influence on downstream rivers. Here, we modeled ephemeral stream water contributions to the contiguous United States network of more than 20 million rivers, lakes, and reservoirs, finding that ephemeral streams contribute, on average, 55% of the discharge exported from regional river systems, as defined by the United States Geological Survey.

The costs of "costless" climate mitigation.

The IPCC and leading economic models have different ideas about emissions reduction costs.

Why marginal CO emissions are not decreasing for US electricity: Estimates and implications for climate policy.

Marginal emissions of CO from the electricity sector are critical for evaluating climate policies that rely on shifts in electricity demand or supply. This paper provides estimates of marginal CO emissions from US electricity generation using the most recently available and comprehensive data. The estimates vary by region, hour of the day, and year to year over the last decade.