Two Existential Threats
The Intergovernmental Panel of Climate Change (IPCC) released a much anticipated report today. It says what we already know, that “emissions of greenhouse gases from human activities are responsible for approximately 1.1°C of warming since 1850-1900, and finds that averaged over the next 20 years, global temperature is expected to reach or exceed 1.5°C of warming.
To put 1.5°C in perspective, it is expected that at that level “of global warming, there will be increasing heat waves, longer warm seasons and shorter cold seasons. At 2°C of global warming, heat extremes would more often reach critical tolerance thresholds for agriculture and health, the report shows. Propelled by human activity, the IPCC says climate change is actively “bringing multiple different changes in different regions – which will all increase with further warming.” We’re currently experiencing examples of this:
- Climate change is intensifying the water cycle. This brings more intense rainfall and associated flooding, as well as more intense drought in many regions.
- Climate change is affecting rainfall patterns. In high latitudes, precipitation is likely to increase, while it is projected to decrease over large parts of the subtropics. Changes to monsoon precipitation are expected, which will vary by region.
- Coastal areas will see continued sea level rise throughout the 21st century, contributing to more frequent and severe coastal flooding in low-lying areas and coastal erosion. Extreme sea level events that previously occurred once in 100 years could happen every year by the end of this century.
- Further warming will amplify permafrost thawing, and the loss of seasonal snow cover, melting of glaciers and ice sheets, and loss of summer Arctic sea ice.
- Changes to the ocean, including warming, more frequent marine heatwaves, ocean acidification, and reduced oxygen levels have been clearly linked to human influence. These changes affect both ocean ecosystems and the people that rely on them, and they will continue throughout at least the rest of this century.
- For cities, some aspects of climate change may be amplified, including heat (since urban areas are usually warmer than their surroundings), flooding from heavy precipitation events and sea level rise in coastal cities.
The IPCC report emphasized that “the evidence is clear that carbon dioxide (CO2) is the main driver of climate change, even as other greenhouse gases and air pollutants also affect the climate. A co-chair of the IPCC Working Group 1, Panmao Zhai, made clear that ‘stabilizing the climate will require strong, rapid, and sustained reductions in greenhouse gas emissions, and reaching net zero CO2 emissions. Limiting other greenhouse gases and air pollutants, especially methane, could have benefits both for health and the climate.’ Even with rapid action, IPCC expects that “while benefits for air quality would come quickly, it could take 20-30 years to see global temperatures stabilize”.
The IPCC report, called a red-flag by the Secretary of the United Nations, expects the world to reach 1.5°C in all of it’s scientific models within the next twenty years. As mentioned, this can be avoided if the world acts quickly.
Today also marks the seventy-sixth anniversaries of one of the largest human-made disasters in the world. Three days after dropping a nuclear weapon on Hiroshima, killing 140,000 Japanese, the U.S. dropped a slightly stronger bomb on Nagasaki on August 9, 1945, killing another 74.000. The bombs dropped on Hiroshima and Nagasaki were the only nuclear bombs used in warfare. This information from ICAN – the Nobel Prize winning International Campaign to Abolish Nuclear Weapons – also describes the the inability to provide aid in the aftermath of the bombings, and the resulting health hazards from nuclear blasts. “Leukaemia increased noticeably among survivors. After about a decade, survivors began suffering from thyroid, breast, lung and other cancers at higher than normal rates.”

This January, because of the work of ICAN, the Treaty on the Prohibition of Nuclear Weapons (TPNW) became part of international law. The TPNW “prohibits nations from developing, testing, producing, manufacturing, transferring, possessing, stockpiling, using or threatening to use nuclear weapons, or allowing nuclear weapons to be stationed on their territory. It also prohibits them from assisting, encouraging or inducing anyone to engage in any of these activities.”
It is true that this injunction is only legally binding on nations (or more correctly, states) that has ratified the TPNW. However, that should be good news. Only nine states have nuclear weapons, and none of them actually want to use them.
It is possible that these nine states know that not only would any use of a nuclear weapons lead to a a uncontrollable war but that a nuclear war would lead to a disastrous effect on the environment and the ecosystem and that this “nuclear winter” could last a decade.
The climate emergency we have created and the prospect of use of nuclear weapons leading to a climate breakdown known as “nuclear winter” are the two major existential crises humanity faces. These two threats are connected and are man-made. The good news is because these threats to humanity are man-made, they can be undone to a large extent.
In 2019 The Guardian reported that twenty companies “can be directly linked to more than one-third of all greenhouse gas emissions in the modern era”. A couple months earlier, Forbes reported that “the single largest consumer of energy in the U.S., the Department of Defense is the world’s single largest institutional consumer of petroleum” and that the D.OD. has a larger carbon footprint than most countries. The twenty companies that can be linked to greenhouse emissions over the last fifty years are the same companies that supply the D.O.D.
The climate emergency or the prospect of a nuclear winter should not make us give up but rather propel us into action to undo these existential threats. Our propensity for war, which is tied to our love of consumerism and our need for the requisite resources, must end before we end ourselves. I’ve written recently about advocating for social justice and about reaching out to policy-makers such as elected members of Congress. While we must each choose our own path it is important to remember that inaction is insufficient.