Californians have seen climate change happen before their eyes. Long droughts, forest fires, rising sea levels, coastal flooding and coastal erosion have come to the lives of residents of the West Coast.

12 million Californians have had firsthand experience with drought, equivalent to one-third of the state’s population. The longest drought lasted 376 weeks, starting Dec. 27, 2011, and ending in March 2019. The peak of the drought occurred the week of July 29, 2014, when 100% of California’s land suffered from drought and 58.41% of it was in an extraordinary drought situation, absolutely bone-dry.

Drought has an impact on how easily grasslands and forests burn. As of the writing of this op-ed, 23,000 hectares of forest and pasture are burning in Coalinga in central California. Meanwhile, sea levels around San Francisco have risen 6 inches since 1950. The pace of the rise has increased over the past 10 years, and sea levels are now rising by about an inch every 10 years.

This is the reality experienced by California’s residents, although President Donald Trump doesn’t think much of it. He is blatantly anti-science: In 2018, Trump made international headlines after he expressed doubt over the National Climate Assessment of his own government.

Although Trump’s rhetoric about climate change has softened recently, this reasoning is purely political. Many Republicans have begun to express belief regarding the awful effects of climate change. A survey commissioned by the American Conservation Coalition showed that 67% of Republican millennial voters believed that political parties have to do more for climate change. On Twitter, Trump no longer seems as hostile to climate change. However, the Trump administration has been, and still is, hostile to California.

In October 2019, the federal government sued California over its cap-and-trade agreement with Quebec, Canada. In cap-and-trade programs, a limit (the “cap”) is placed on greenhouse gas emissions to stop further growth in certain sectors. Then, a trajectory is developed for how this cap will decrease over time to reach the desired level of emissions on a target date. Allowances are created to enforce the cap, with each allowance conveying a right to emit one metric ton of carbon dioxide equivalent. These allowances are distributed to regulated entities either through direct allocation by the government or through auctions. Once the allowances are distributed, the regulated entities are free to trade them with one another. Through this trading, emissions are reduced in the most efficient manner.

California was considered to have violated the Constitution because it’d entered a foreign relations agreement that should be under the authority of the federal government. In addition, California’s action was seen as contradictory to Trump’s foreign policy, which absolved to withdraw from international agreements on climate change.

Contrary to the federal government’s beliefs, California’s relationship with Quebec in limiting and trading carbon emissions is constitutional, a U.S. District Court ruled. The U.S. District Court for the Eastern District of California said the Trump administration had “failed to identify a clear and express foreign policy that directly conflicts with California’s cap-and-trade program.”

Climate disasters have come and gone, such as the annual devastating forest fires, but at the same time, research shows that these crises will only escalate in California if the United States’ business-as-usual commitment continues.

Climate change is expected to increase the average temperature in California by 0.5 to 2 degrees Celsius in the next 30 years and by 1.5 to 5.8 degrees Celsius in the last 30 years of the 21st century. Rainfall will decrease by about 5% in the Sacramento area and by 15% or more in Southern California. In addition, California’s snowbanks are expected to decline and melt earlier.

When these effects are combined, droughts will get worse, and California’s agricultural output will decrease — gross annual agricultural income could fall to $3 billion by 2050. The increase in temperatures and decrease in rainfall will intensify the forest fires that have damaged California. This is a state of climate emergency.

California has set a target to reduce greenhouse gas emissions to 1990’s levels by 2020, to 40% below the 1990 levels by 2030 and to 80% below by 2050. California also has a goal of achieving 100% carbon-free electricity and carbon neutrality by 2045.

The climate problem’s solution is now more reliant on political motivations than on constitutional matters. Countries of comparable size to California have long been involved in cross-border activities. Over the past half-century, states and cities have worked on hundreds to thousands of agreements with foreign national and subnational governments on various topics, including trade, tourism, transportation, family matters, sister relations, security, traffic regulations, environment and agriculture.

The Constitution establishes exclusive powers of the national government over certain aspects of foreign affairs. However, neither Congress nor the president has used their full authority. This condition has created a “gray zone” of federalism in foreign affairs that states such as California have taken action in.

California has once again taken the lead in pioneering environmental regulations to address one of the most important environmental threats of our time. The success of California’s cap-and-trade program is vital to national and international efforts to reduce greenhouse gas emissions. If the program is successful, other states should join California by implementing cap-and-trade programs of their own, especially in light of the federal government’s unwillingness to take protective environmental action. Climate change is an issue without borders, after all, and impacts every person on the planet. We must do all that we can to mitigate its effects.

Given that the United States is the second-largest emitter of greenhouse gases in the world and one of the primary barriers to international action, a successful California program could be the catalyst for serious international efforts to reduce greenhouse gases to avert the worst impacts of climate change.