Since the beginning of the year:

• Wildfires have burned 805,000 acres across the country, causing four deaths in New Mexico and Colorado.

• More than 400 tornadoes have touched down in the U.S., killing 13 people and destroying dozens of homes and buildings.

• In January, a study published in the journal Environmental Science & Technology concluded that the world's production of chemical compounds has reached alarming levels, a fifty-fold increase since 1950. In short, said one of the researchers, “the total mass of plastics now exceeds the total mass of all living animals.”

In the face of these cataclysmic statistics, the notion of Earth Day seems quaint. How can anyone think that a day of picking up litter or visiting parks possibly could have an impact when chemical pollution and the extreme weather events spawned by climate change threaten to make our planet uninhabitable?

When the holiday was first celebrated, in 1970, the outlook was similarly bleak. Rachel Carson had alerted the world to the dangers of pesticides in her book, “Silent Spring,” just eight years prior. In Cleveland the previous November, the Cuyahoga River — a cauldron of oil and other pollutants — caught fire.

The specter of a spring without bird song and a blazing river turned the tide for the environmental movement, prompting President Richard M. Nixon to create the Environmental Protection Agency by executive order in 1970.

In some ways, much progress has been made since then. The passage of the Clean Air Act and the Safe Drinking Water Act in the 1970s, and Superfund legislation in 1980, have given teeth to governmental efforts to keep our air and water clean and to correct past mistakes.

But we would be naive to think that governmental regulations, which face a constant threat from business and anti-government interests, have solved any of these problems.

Connecticut ranks 12th in the nation in cancer cases. Scientists cannot pinpoint how many cases have environmental causes, and high cancer rates are influenced by genetics, lifestyle and other factors.

Still, the state's down-wind proximity to pollution centers such as New Jersey and the Midwest affects its air quality, which regularly violates federal clean air standards.

The state also has 13 Superfund sites, including the Naval Submarine Base in Groton. While many of these sites, including the Sub Base, have undergone extensive remediation and continued monitoring, they provide another barometer by which to measure pollution.

So has Earth Day become an empty gesture, a feel-good observance that has little impact on the environment?

Let's remember that Earth Day was never expected to solve the country's environmental problems. It has always been a day of witnessing and awareness, a way to remind the public that much still needs to be done to protect our air, land and water.

Part of its function is educational: By involving children, we help raise tomorrow's stewards of the natural world.

The holiday also keeps environmental issues in the local consciousness. If you're on the roadside picking up litter, your complacent neighbors will take notice. Some of the litter bugs may feel a little chagrined, as well.

Taking the time to explore local parks and trails reminds us that we aren't the only ones on this planet. By despoiling the environment we ruin the habitat for the mammals, birds and other reptiles that call Earth home.

And maybe, some of us marking the day will think about how to make a difference after it is over. We can find an environmental organization to donate to; start composting or recycling; plant a tree; or write a letter to our senator or representative.

The planet's outlook will remain serious long after the last Earth Day poster is taken down. But at least the day gives us some hope.