The concept of “flattening the curve” brilliantly communicated the need for rapid public health measures to avoid overwhelming health system capacity during the COVID-19 pandemic (Figure). The curve is flattened by behaviors that reduce the rate of contagion spread and enable time to replenish and innovate resources. “Flattening the curve” applies to any exponential process. We've embraced it for SARS-CoV-2, and we have seen how sustained, dedicated, and tightly coordinated effort can alter the course of nature. Environmental destruction is also an exponential process. For our long-term survival, we must “flatten the curve” of exponential environmental damage. Herd immunity does not apply to depletion of the earth's finite resources.

The 2018 Intergovernmental Panel on Climate Change (IPCC) Special Report on Global Warming of 1.5°C was prepared by 91 authors from 40 countries, and it included over 6,000 scientific references. This IPCC Special Report described the need to rapidly transition our economy to reduce greenhouse gas emissions by 45% from 2010 levels by 2030 and to reach “net zero” by 2050. Swift reduction is required to keep average global surface temperature rise below 1.5°C and avert the worst predicted harms to global health: increased frequency and severity of storms, flooding, drought, wildfires, and food and water insecurity, political instability, and population displacement. The impact of climate change is already being felt and will become far more devastating over the coming years and decades unless we flatten the greenhouse gas curve (Global Warming of 1.5C: An IPCC Special Report, 2018).

Globally, health care contributes 4.6% of anthropogenic greenhouse gas emissions, excluding waste anesthetic gases (Lancet 2019;394:1836-78). Health care is the most carbon intensive service sector in developed countries (Environ Res Lett 2019;14). The global pharmaceutical industry generates more greenhouse gas emission per operating revenue than the automotive industry (J Clean Prod 2019;214:185-94). The United States leads the world in health care greenhouse gas emissions per capita, without commensurate beneficial health outcomes (Lancet 2019;394:1836-78). U.S. health care generates nearly 10% of total national greenhouse gas emissions, and 9% of criteria air pollutants, largely from burning fossil fuels. Health damages stemming from U.S. health care pollution are in the same order of magnitude as deaths from preventable medical errors (Am J Public Health 2018;108:S120-2). Needless to say, we are spending billions of dollars preventing injuries from avoidable medical errors and don't even talk about the adverse health effects of health care pollution. That is starting to change with international calls for climate change mitigation within the health care sector (Environ Res Lett 2019;14; Lancet 2019;394:1836-78; Am J Public Health 2018;108:S120-2; BMJ 2020;368:m970).

“The impact of climate change is already being felt and will become far more devastating over the coming years and decades unless we flatten the greenhouse gas curve.”

Health care spending presently accounts for 10% of global GDP. This makes health care purchasing power a potentially formidable force to drive transformation to a sustainable global economy. Health professionals are respected and well-positioned to engage members of our communities in socially responsible behaviors and influence public policy. As with the COVID-19 pandemic, we need to use our voices and lead by example to address the climate crisis.

In January of this year, the National Health Service (NHS) in England launched a major new initiative aimed to build a “greener NHS.” Their goal is to achieve net zero emissions as quickly as possible, faster than their 2050 legal mandate under the British Climate Act of 2008. With 1.3 million workers, the NHS is the largest employer in Europe. A large majority of NHS employees strongly support the principle that the NHS should reduce its environmental impact and function in a sustainable manner (BMJ 2020;368:m970; Such engagement is essential to achieve rapid systemic transformation.

Several national health system studies have demonstrated that more than half of the carbon footprint can be attributed to embedded emissions in the supply chain – drugs and medical devices (BMJ 2020;368:m970; Resour Conserv Recy 2020;160:104862). Improving health care quality requires increasing efficiency through reducing waste, preventing medical errors, eliminating unnecessary care, and preventing illness. High-quality care is more sustainable care: clinically, financially, and environmentally. However, efficiency improvements alone cannot get a health system to net zero (BMJ 2020;368:m970).

The COVID-19 pandemic has forced us to re-examine our consumption practices in health care. It has heighted awareness of our wastefulness. It also highlighted our short-sighted reliance on single-use disposable supplies and devices, many of which increase cost without any evidence of patient safety benefit. These items are manufactured worldwide, often far from the point of use, and delivered just in time. This practice reduces the need for storage space and ensures supplies don't expire, but also renders the supply chain vulnerable to interruptions that lead to critical shortages.

Early on in the pandemic, when the nature of disease transmission was less well understood and best practices were still being developed, it was prudent to take extra precautions and rely heavily on single-use disposable materials. However, the supply chain was disrupted at the same time that demand for items such as personal protective equipment (PPE) and sedative agents skyrocketed. Health systems quickly ran out of critical supplies, including N95 masks, impermeable gowns, and single-use disposable video-laryngoscope blade covers, and had to improvise more sustainable approaches.

Many single-use disposable items can be safely and routinely sterilized by tightly regulated third-party reprocessors; however, most health systems did not have existing contracts with reprocessors nor protocols for routinely recovering devices. Thus, it took some time for systems to develop internal protocols to safely reprocess and reuse these items.

Now that we're realizing we can and must reuse more items, the plastics industry has been exploiting fears about COVID-19 to drive up consumption of single-use disposables. For example, there is coordinated industry effort to convince policymakers, businesses, and the public that reusable bags are unsafe and that single-use plastic is safer ( As a result, municipalities and businesses have delayed or rolled back bans on single-use plastic, despite the virus spreading primarily through breathing aerosolized droplets rather than contacting surfaces. Local dry cleaners have started advertising that dry-cleaning kills viruses. Sure, it does, but so does my laundry machine. Single-use medical device manufacturers are cashing in on the same fears.

Infection prevention is essential. With the COVID-19 crisis, we have proven we can safely reuse many medical devices – both single-use disposable and reusable. We had to. We must recognize that planetary resources are finite, whether shortages are experienced from pandemics or weather-related disasters, and we must actively seek to conserve materials at every moment.

Now is the time to take advantage of the COVID-19 disruption and make bold changes to do what is necessary to flatten the greenhouse gas curve. While we can't stop climate change, if we aggressively reduce our greenhouse gas emissions now, we can slow down the effects today. That would give society a chance to adapt, just like social distancing helped slow down the patient surge and enabled health systems to build their capacity during the COVID-19 pandemic.

The only difference between the COVID-19 pandemic and climate crisis curves is that the time scale is different. After the IPCC Special Report came out, people said that a decade wasn't nearly enough time for societal transformation. COVID-19 has disproven that. People and governments across the world have quickly come together to do what is necessary to flatten the COVID-19 curve. By comparison, a decade is incredibly doable, if we approach the climate crisis with the same urgency and ingenuity. Moreover, unlike the devastating economic shutdown from the COVID-19 pandemic, flattening the greenhouse gas curve provides ample opportunities for economic growth through a greener economy.