The combination of a health crisis, economic distress and social unrest is unprecedented in our lifetimes. The pandemic is a sign of our broken relationship with nature, and recent civil disruption is a consequence of our broken social contract as a community. Unchecked climate change will cause even greater disruptions. It is within our capacity to slow the progression of climate change and adapt to its effects, but only by making enlightened decisions based on solid scientific evidence. That means putting scientifically literate, responsible people into government.

Climate change is causing increased droughts, floods, wildfires, severe storms, ecosystem collapse and sea-level rise worldwide. As traditional farmlands are degraded by climate change, humans invade natural systems putting us in contact with new diseases.

Unlike historical epidemics which originated in our livestock, the most recent pandemics have arisen from wildlife. The trade in wildlife has brought wild animal pathogens into our homes. After the SARS coronavirus epidemic of 2002 scientists warned that without control of the wildlife trade and protection of natural ecosystems, more epidemic diseases were inevitable.

Worldwide it is the poorer countries that are most heavily impacted by climate change; large sections of the tropics are becoming uninhabitable by humans. When living conditions become impossible, humans migrate. Subsequent stresses and fears within the destination countries, due to large numbers of migrants, give rise to demagogues who prove incompetent in a crisis.

Scientists have been warning about climate change for over a century. Carbon dioxide and other greenhouse gases act as a blanket in the atmosphere, trapping heat that would otherwise be reflected out into space.

In 1958 the geochemist Charles Keeling began documenting atmospheric carbon dioxide on Mauna Loa on the island of Hawaii. Pre-industrial levels were 280 ppm or parts carbon dioxide per million parts of air. Last recorded in 1974, 350 ppm was considered a safe level. On Mauna Loa, on June 2, 2020, the measured level was 417.8 ppm, the highest in the past 800,000 years.

Without human-induced climate forcing, over the next few thousand years we would be slowly heading into the next ice age.

However, we are on track for global temperatures of at least 2°C (3.6°F) above pre-industrial levels by 2100. The oceans have absorbed 90% of the excess heat generated by burning fossil fuels, so even if greenhouse gas emissions were cut to zero immediately, we are committed to a warmer world for hundreds of years as the oceans release that heat. It is not enough to stop production of greenhouse gases, challenging as that may be; it is necessary to actively remove them from the atmosphere.

We must stop subsidizing fossil fuels, transition to clean energy sources, price carbon and invest in carbon capture technologies. It is also imperative that we prepare and adapt to inevitable climate change with a green industrial revolution in a just and equitable transition.

While there are many actions that can be taken by individuals, keeping global temperatures below 2°C of warming will take political will and international effort. Leaders must be able to understand the science and act upon it. The pandemic and the civil unrest have exposed how unprepared as a nation we are for challenges.

To rejoin the global community, prevent future pandemics and tackle climate change, citizens must register to vote, vote in general AND primary elections, and support environmentally and socially conscious candidates so that we have a chance at a fairer, greener and more resilient world.

Diane Shepherd, D.V.M., is a veterinarian in Kihei, Maui.