The atmospheric concentration of carbon dioxide (CO2) has recently reached a “milestone” of 400 parts per million (ppm). In some circles, this announcement has been met with consternation and gnashing of teeth. The proper reaction is celebration.

The growth in the atmospheric CO2 concentration over the past several centuries is primarily the result of mankind’s thirst for energy—largely in the form of fossil fuels. According to the World Bank, fossil fuel energy supplies about 80% of the world’s energy production—a value which has been pretty much constant for the past 40 years. During that time, the global population increased by 75%, and global energy use doubled. Global per capita energy use increased, while global energy use per $1000 GDP declined. We are using more energy, but we are using it more efficiently. In the developed world, life expectancy has doubled since the dawn of the fossil fuel era.

Of course, burning fossil fuels to produce energy results in the emission of carbon dioxide into the atmosphere, tipping the natural balance of annual CO2 flux and leading to a gradual build-up.

There are two primary externalities that result from our emissions of carbon dioxide into the atmosphere—1) an enhancement of the greenhouse effect, which results in an alteration of the energy flow in the earth’s climate and a general tendency to warm the global average surface temperature, and 2) an enhancement of the rate of photosynthesis in plants and a general tendency to result in more efficient growth and an overall healthier condition of vegetation (including crops). There’s incontrovertible evidence that the planet is both warmer and greener than it was 100 years ago.

As we continually document (see here for our latest post), more and more science is suggesting that the rate (and thus magnitude at any point in time) of CO2-induced climate change is not as great as commonly portrayed. The lower the rate of change, the lower the resulting impact. If the rate is low enough, carbon dioxide emissions confer a net benefit. We’d like to remind readers that “it’s not the heat, it’s the sensitivity,” when it comes to carbon dioxide, and the sensitivity appears to have been overestimated.

As new science erodes the foundation of climate worry, new technologies are expanding recoverable fossil fuel resources. Horizontal drilling and hydraulic fracturing have opened up vast expanses of fossil fuel resources—mainly natural gas—that were untouchable just a few years ago. The discovery that the world is awash in hundreds of years of recoverable fuels is a game-changer, given the strong correlation between energy use per capita and life expectancy.

400ppm of carbon dioxide in the atmosphere should remind us of our continuing success at expanding the global supply of energy to meet a growing demand. That success which ultimately leads to an improvement of the global standard of living and a reduction in vulnerability to the vagaries of weather and climate.

400pm is cause for celebration. “A world lit only by fire” is not.