Every month, SCIENTIFIC AMERICAN—the longest-running magazine in the U.S. and an authoritative voice in science, technology and innovation—provides insight into scientific topics that affect our daily lives and capture our imagination, establishing the vital bridge between science and public policy.

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The Keystone XL pipeline is the only economical way to distribute oil from the Canadian tar sands to the U.S. Climate scientists believe, however, that the tar sands will speed up carbon emissions, pushing global carbon to dangerous levels. These findings suggest that the fate of the planet may partially hinge on President Barack Obama’s decision on whether or not to allow the Keystone project in the fall. See: Environment: Greenhouse Goo

Some tuberculosis strains have become resistant to our current treatment regiments, more deadly and able to spread much quicker. Although most developed and developing countries have treatment measures for tuberculosis, in 2011 the bacteria killed 1.4 million people, and infected another nine million, around the world. The next wave of options for fighting TB will need to consider new genetic and environmental strategies to protect people against mutating forms. See: Global Health: The Diabolical Genius of an Ancient Scourge

• The fatal explosion of the fertilizer plant in West, Tex., shines a light on the lack of governance and policing for potentially dangerous industrial sites. The Occupational Safety and Health Administration had not checked on it since 1985. Part of the problem is funding: OSHA relies on 2,200 inspectors to monitor more than eight million work sites and safeguard 130 million workers. The 2013 federal budget sequester is further slicing away at these resources. OSHA and Department of Homeland Security need to be more vigilant in inspecting and verifying the safety of such sites. See: Science Agenda: Exploded Trust

• Scientists are reconsidering the safety of computed tomography (CT) scans, which are a commonly used medical-imaging technique because they give more detailed picture than a standard x-ray. CT scans can expose a person to 150 to 1,100 times more radiation than conventional x-rays and thereby damage DNA and cells in the body. Since the U.S. Food and Drug Administration does not regulate how CT scanners are used or set dose recommendations, different medical centers are using different radiation exposures—some much too high. Physicians and scientists are now working on both standardizing procedures for adult CT scans and creating scanners that can provide the same amount of detail while reducing radiation exposure, perhaps by 75 percent. See: The Science of Health: Do CT Scans Cause Cancer?