Funding Climate Action: Pathways for Philanthropy

Increased greenhouse gas pollution is warming the planet quickly, threatening people, cultures, ecosystems, and global stability. We need a worldwide transition to clean, safe, accessible energy. This transition is complex and requires steady, staged progress. Too often, strategies for addressing the twin challenges of protecting the planet and promoting clean energy access have been slowed by divisions between and among nations, governments at all levels, the private sector, nonprofits, and advocates. At risk are the people and communities that need solutions.This report is a call to action. The solutions necessary to combat climate change are systemic and require collaboration across the public, private, nonprofit, and philanthropic sectors. Fortunately, there are also hopeful signs of progress, both globally and in the U.S. In the last few years, we have seen an acceleration of government funding, significant Net Zero commitments from corporations, and an important increase in philanthropy focused on climate adaptation and mitigation.

The Basic Concepts of Accounting

The Basic Concepts of Accountin

Chandra and XMM-Newton Observations of the Double Cluster Abell 1758

Abell 1758 was classified as a single rich cluster of galaxies by Abell, but a ROSAT observation showed that this system consists of two distinct clusters (A1758N and A1758S) separated by approximately 8\arcmin (a projected separation of 2 Mpc in the rest frame of the clusters). Only a few galaxy redshifts have been published for these two clusters, but the redshift of the Fe lines in the Chandra and XMM-Newton spectra shows that the recessional velocities of A1758N and A1758S are within 2,100 km s$^{-1}$. Thus, these two clusters most likely form a gravitationally bound system, but our imaging and spectroscopic analyses of the X-ray data do not reveal any sign of interaction between the two clusters. The Chandra and XMM-Newton observations show that A1758N and A1758S are both undergoing major mergers. A1758N is in the late stages of a large impact parameter merger between two 7 keV clusters. The two remnant cores have a projected separation of 800 kpc. Based on the measured pressure jumps preceding the two cores, they are receding from one another at less than 1,600 km s$^{-1}$. The two cores are surrounded by hotter gas ($\mathrm{kT}=9$--12 keV) that was probably shock heated during the early stages of the merger. The gas entropy in the two remnant cores is comparable with the central entropy observed in dynamically relaxed clusters, indicating that the merger-induced shocks stalled as they tried to penetrate the high pressure cores of the two merging systems.Each core also has a wake of low entropy gas indicating that this gas was ram pressure stripped without being strongly shocked (abridged). (A copy of the paper with higher resolution images is available at http://asc.harvard.edu/~lpd/a1758.ps).Comment: paper plus 13 figure