This Earth Day, it almost feels like we should be carving some turkey. Why? Because we have a lot to be thankful for since the first Earth Day event occurred 49 years ago.

We should be thankful that the gloom-and-doom predictions made throughout the past several decades haven't come true. Fear-mongering about explosive population growth, food crises and the imminent depletion of natural resources have been a staple of Earth Day events since 1970. And the common thread among them is that they've stirred up a lot more emotions than facts.

"By the year 2000, if present trends continue, we will be using up crude oil at such a rate ... that there won't be any more crude oil," ecologist Kenneth Watt warned around the time of the first Earth Day event. "You'll drive up to the pump and say, `Fill 'er up, buddy,' and he'll say, `I am very sorry, there isn't any.'" Watt also warned of global cooling and nitrogen buildup rendering all of the planet's land unusable.

The issue, however, is that present trends don't continue. They change dramatically for a number of reasons. Innovation happens. Consumer behavior changes. Importantly, price signals play a huge role in communicating information to energy producers as well as consumers.

Higher prices at the pump encourages companies to extract and supply more oil. Expensive gas prices, meanwhile, motivate entrepreneurs to invest in alternatives to oil, whether that's batteries, natural gas vehicles or biofuels. Drivers will examine their consumption options as well, whether carpooling, finding alternative modes of transportation, or, over time, purchasing a more fuel-efficient vehicle.

Here we are, 19 years past Watt's arbitrary deadline, and drivers are pulling up to the pump saying, "Fill 'er up, buddy" (figuratively speaking, as Watts also didn't foresee self-service stations) without any cause for concern. Thanks to human ingenuity and the entrepreneurial drive of energy producers, the United States is now the world's largest oil producer according to the U.S. Energy Information Administration and continually breaking records.

While global energy poverty and food insecurity remain a pressing challenge, the problem is getting much better, not worse. World Bank and United Nations data show extreme poverty and global hunger has noticeably dropped since 1970. And according to International Energy Agency, the number of people without access to electricity fell to below 1 billion people for the first time.

Clearly, there's work to be done. But signs are pointing in the right direction.

In the United States, the common perception is that the country's environmental state is deteriorating. On the contrary, through investment in new technologies, and through legislation, environmental trends have improved significantly in the United States. Pollutants known to cause harm to public health and the environment are declining. According to the Environmental Protection Agency's latest air quality trends report, the combined emissions of the six common air pollutants have decreased 73 percent between 1970-2017.

We should be thankful for economic liberties that provide people with the means to protect the environment. As a country grows economically, it increases the financial ability of its citizens and businesses to care for the environment and reduce pollutants emitted from industrial growth. Countries with greater economic freedoms have cleaner environments and greater environmental sustainability. The Heritage Foundation's Index of Economic Freedom and Yale University's Environmental Performance Index show a highly positive correlation between a country's environmental performance and its economic freedom.

Freer economies have access to more products and technologies that make our lives healthier and the environment cleaner. For instance, the availability of simple products such as soaps, cleaners, and detergents makes our homes dramatically cleaner and healthier. The development of sanitation systems and availability of garbage collection greatly reduce many types of diseases and reduce toxins in the air and water.

These products and services may not be what immediately comes to mind on Earth Day, but they've have an enormous impact on cleaning up the planet.

And we should be thankful for clearly defined and protected private property rights. One of the first lessons I learned in economics is that nobody washes a rental car because you don't care for what you don't own.

Property rights are a central hallmark in the United States and around the world for improved environmental stewardship, conservation and health of species, wildlife, habitats, forests and other resources. The absence of enforced private property rights in developing country remains one of the largest barriers to improved prosperity and environmental well-being.

Catastrophic but unlikely gloom-and-doom predictions will continue to grab media headlines, but free societies with the protection of property rights are tried and true pathways to a healthier, cleaner world. As we reflect on the progress we've made as a free society, let's celebrate and be thankful.