The Treaty on the Prohibition of Nuclear Weapons (TPNW) is based upon a body of indisputable evidence, documented by scientists, health professionals, and experts in crisis management and response, that the consequences of nuclear weapons use are catastrophic, global, and without remedy. Nuclear weapons—as has been said repeatedly by the advocates for this Treaty in both States and civil society—are an existential threat to humanity which belong in no one’s hands.

 

Much of the evidence underpinning the TPNW has been accumulated over the decades since the US atomic bombings of Hiroshima and Nagasaki; more was learned during the years of nuclear weapons testing and the Cold War; and we have made significant additions to our knowledge in recent years, particularly with regard to the devastating global climate effects of nuclear war.

 

In this paper, we will summarize the blast, heat, and radiation effects of nuclear weapons; review the impacts on climate from both limited and large-scale nuclear conflicts; and present new data about climate effects that has been published since the adoption of the Treaty.

 

Just as a thorough understanding of the catastrophic consequences of nuclear weapons compelled States to negotiate and adopt the TPNW in 2017, keeping updated evidence at the forefront of all future deliberations—including at this 1MSP—is essential to understanding the importance of the Treaty, fully implementing its provisions, and achieving its ultimate and most urgent goal—the total elimination of nuclear weapons.