656 Items

Earthrise over the Moon

NASA/Bill Anders

Journal Article - Nature Sustainability

Policy Design for the Anthropocene

    Authors:
  • Thomas Sterner
  • Edward B. Barbier
  • Ian Bateman
  • Inge van den Bijgaart
  • Anne-Sophie Crépin
  • Ottmar Edenhofer
  • Carolyn Fischer
  • Wolfgang Habla
  • John Hassler
  • Olof Johansson-Stenman
  • Andreas Lange
  • Stephen Polasky
  • Johan Rockström
  • Henrik G. Smith
  • Will Steffen
  • James E. Wilen
  • Francisco Alpízar
  • Christian Azar
  • Donna Carless
  • Carlos Chávez
  • Jessica Coria
  • Gustav Engström
  • Sverker C. Jagers
  • Gunnar Köhlin
  • Åsa Löfgren
  • Håkan Pleijel
  • Amanda Robinson
| 2019

The authors examine the complexities of designing policies that can keep Earth within the biophysical limits favorable to human life.

iceberg in North Star Bay

NASA/Jeremy Harbeck

Presentation - Belfer Center for Science and International Affairs, Harvard Kennedy School

International Collaboration in Arctic Science: Progress and Prospects

| Dec. 13, 2018

Professor John P. Holdren gave this presentation at the Session on 60 Years of Arctic & Antarctic Science at the American Geophysical Union Fall Meeting in Washington, D.C., on December 13, 2018.

Sunset on the Indian Ocean

NASA

Journal Article - Environmental Research Letters

Stratospheric Aerosol Injection Tactics and Costs in the First 15 Years of Deployment

| 2018

We review the capabilities and costs of various lofting methods intended to deliver sulfates into the lower stratosphere. We lay out a future solar geoengineering deployment scenario of halving the increase in anthropogenic radiative forcing beginning 15 years hence, by deploying material to altitudes as high as ~20 km. After surveying an exhaustive list of potential deployment techniques, we settle upon an aircraft-based delivery system. Unlike the one prior comprehensive study on the topic (McClellan et al 2012 Environ. Res. Lett. 7 034019), we conclude that no existing aircraft design—even with extensive modifications—can reasonably fulfill this mission. However, we also conclude that developing a new, purpose-built high-altitude tanker with substantial payload capabilities would neither be technologically difficult nor prohibitively expensive. We calculate early-year costs of ~$1500 ton−1 of material deployed, resulting in average costs of ~$2.25 billion yr−1 over the first 15 years of deployment. We further calculate the number of flights at ~4000 in year one, linearly increasing by ~4000 yr−1. We conclude by arguing that, while cheap, such an aircraft-based program would unlikely be a secret, given the need for thousands of flights annually by airliner-sized aircraft operating from an international array of bases.

Satellite image of Hurricane Katia (left) making landfall over the Mexican state of Veracruz, Hurricane Irma (center) approaching Cuba, and Hurricane Jose reaching peak intensity

NOAA

Journal Article - Review of Environmental Economics and Policy

Recommendations for Improving the Treatment of Risk and Uncertainty in Economic Estimates of Climate Impacts in the Sixth Intergovernmental Panel on Climate Change Assessment Report

| June 04, 2018

Large discrepancies persist between projections of the physical impacts of climate change and economic damage estimates. These discrepancies increase with increasing global average temperature projections. Based on this observation, the authors recommend that in its Sixth Assessment Report (AR6), the Intergovernmental Panel on Climate Change (IPCC) improve its approach to the management of the uncertainties inherent in climate policy decisions.

A petroleum refinery is seen in the background of a residential neighborhood.

AP Photo/David Goldman

- Belfer Center for Science and International Affairs, Harvard Kennedy School Belfer Center Newsletter

NOVA: Holdren, Schrag Explain Climate Change

| Summer 2018

In a new PBS NOVA documentary, Decoding the Weather Machine, Holdren notes that climate science—accumulating since Fourier’s time—proves that humans are responsible for the big increases in heat-trapping gases in the atmosphere.

ash in the upper atmosphere

Wikimedia CC/Peter Shanks

Journal Article - Environmental Politics

Fast, Cheap, and Imperfect? US Public Opinion about Solar Geoengineering

| May 2018

Solar geoengineering, which seeks to cool the planet by reflecting a small fraction of sunlight back into space, has drawn the attention of scientists and policymakers as climate change remains unabated. Unlike mitigation, solar geoengineering could quickly and cheaply lower global temperatures. It is also imperfect. Its environmental impacts remain unpredictable, and its low cost and immediate effects may result in "moral hazard," potentially crowding out costly mitigation efforts. There is little understanding about how the public will respond to such tradeoffs.