The Pentagon emits more greenhouse gases than any other department in the United States.

For more than a decade, scientists and security analysts have been warning that global warming is a potential national security issue.

They predict that the consequences of global warming-sea level rise, severe storms, famine and reduced access to fresh water-may lead to political instability in some parts of the world, and large-scale migration and refugee crises will soon occur.

Some people worry that war may follow.

However, with a few exceptions, the significant contribution of the US military to climate change has received little attention. Although the U.S. Department of Defense has greatly reduced the consumption of fossil fuels since the beginning of this century, it is still the largest oil consumer in the world, and therefore one of the largest greenhouse gas emitters in the world. I have studied war and peace for 40 years. But when I started to co-teach a course on climate change, focusing on the Pentagon's response to global warming, I only paid attention to the scale of greenhouse gas emissions of the US military. However, the Department of Defense is the largest fossil fuel consumer in the United States, accounting for 77% to 80% of federal energy consumption since 200 1. In a recent research report published by Brown University's War Cost Project, KDSP calculated the greenhouse gas emissions of the United States. Equivalent to 1975 to 20 17.

Today, China is the largest emitter of greenhouse gases in the world, followed by the United States. In 20 17, the total greenhouse gas emissions of the Pentagon exceeded 59 million metric tons of carbon dioxide equivalent. If it were a country, it would become the 55th largest emitter of greenhouse gases in the world, surpassing Portugal, Sweden or Denmark.

The biggest sources of military greenhouse gas emissions are buildings and fuels. The Ministry of National Defense has about 560,000 buildings, accounting for about 500 domestic and overseas military facilities, accounting for about 40% of its greenhouse gas emissions. For example, in fiscal year 20 16, the Ministry of National Defense consumed about 86 million barrels of fuel for combat purposes.

Why does the army consume so much fuel? "Military weapons and equipment consume too much fuel, and the relevant measure of defense planners is often gallons per mile."

The plane is particularly thirsty. For example, the B-2 stealth bomber has more than 25,600 gallons of jet fuel, burns 4.28 gallons per mile, and emits more than 250 metric tons of greenhouse gases within 6,000 nautical miles. KC- 135R aerial tanker consumes about 4.9 gallons per mile.

A mission consumes a lot of fuel. 2017,65438+10, two B-2B bombers and 15 aerial tankers departed from Whiteman air force base, and the journey exceeded 12000 miles, bombing Libyan targets and killing about 80 suspected Libyan militants. Excluding the emissions from oil tankers, the greenhouse gas emitted by B-2 oil tankers is about 65,438+0,000 metric tons.

It is not easy to quantify military emissions and calculate the greenhouse gas emissions of the Ministry of National Defense. The Defense Logistics Agency tracks fuel procurement, but the Pentagon did not report the Department of Defense's fossil fuel consumption to Congress in its annual budget request.

The Ministry of Energy publishes data on energy production and fuel consumption of the Ministry of National Defense, including data on vehicles and equipment. According to the data of fuel consumption, I estimate that from 200 1 to 20 17, the Ministry of National Defense, including all service departments, emitted1200 million tons of greenhouse gases. This is roughly equivalent to driving 255 million passenger cars a year.

I estimate that the war-related emissions in 200 1 to 20 17 years, including "overseas emergency operations" in Afghanistan, Pakistan, Iraq and Syria, generated more than 400 million metric tons of carbon dioxide equivalent, which is roughly equivalent to the greenhouse effect selenium emissions of nearly 85 million vehicles in one year.

Real and Current Dangers The core task of the Department of Defense is to prepare for potential attacks by human opponents. Analysts have raised objections to the possibility of war and the level of military preparation needed to prevent it, but in my opinion, none of the American rivals-Russian, Iranian, China and North Korea-will definitely attack the United States. It is not a huge standing army, but the only way to reduce the threat posed by these opponents. Arms control and diplomacy can often ease tensions and reduce threats. Economic sanctions will weaken the ability of state and non-state actors to threaten the security interests of the United States and its allies. In contrast, climate change is not a potential risk. It has already begun, bringing real consequences to the United States. If greenhouse gas emissions cannot be reduced, strategists will be more likely to warn of "climate war".

It is an example of military decarburization in the past decade, and the Ministry of National Defense has taken measures including using renewable energy, weathering buildings and reducing the idle time of aircraft on the runway. "KDSP" and "KDSP", the total annual emission of the US Department of Defense decreased from the peak of 85 million tons of carbon dioxide equivalent in 20 17 to 59 million tons in 20 17. As General james mathis said at that time, the goal of the United States is to "liberate from the bondage of fuel" by reducing its military dependence on oil and oil convoys vulnerable to war zones. Since 1979, the United States has always attached great importance to protecting the passage into the Persian Gulf. As national security scholars have said, about a quarter of the fuel used in military operations is used by the US Central Command covering the Persian Gulf region.

With the rapid growth of renewable energy and the reduction of American dependence on foreign oil, it is possible for Congress and the President to reconsider our military mission and reduce the amount of energy used by the armed forces to protect the oil supply in the Middle East.

I agree with military and national security experts that climate change should be the forefront and center of the national security debate in the United States. Cutting greenhouse gas emissions from the Pentagon will help save American lives and reduce the risk of climate conflict.

Neta Crawford, professor and dean of political science at Boston University, said,

This article is reproduced from the dialogue with permission of Zhihu. Read the original. "