What is the global energy demand?

The consumer culture from wealthy nations in North America, Europe, and Asia is rapidly expanding to developing countries, bringing with it an insatiable demand for products, services, and energy.

Energy use is reportedly higher in nations where fewer than 5 percent of the population lives in poverty compared to those where poverty is widespread -- it’s four times greater. For instance, while Americans make up less than 5 percent of the global population, they consume 26 percent of the world’s energy [source: Worldwatch Institute]. Combined, the United States and Canada account for half of the energy consumed by the richest industrialized nations, with Europe consuming 33 percent. However, the energy landscape is shifting. In the first half of 2003, car sales in China surged by 80 percent, with 4 million new privately owned vehicles hitting the roads -- all contributing to fossil-fuel consumption [source: Worldwatch Institute].

Energy consumption encompasses the sources that produce our power: oil, coal, natural gas, and alternatives such as solar, wind, hydropower, and biofuels. (For example, Brazil generates electricity from burning sugarcane waste.) Currently, the world uses 15 terawatts of power from these combined sources [source: The Economist]. How much power is 15 terawatts? Let’s break it down into familiar terms: watts. A typical household lightbulb uses 100 watts. One terawatt could simultaneously power around 10 billion 100-watt lightbulbs [source: Steacie Institute for Molecular Sciences]. Developing countries collectively consume 30 percent of the world's energy, but as their populations and economies grow, energy demand is expected to increase by 95 percent. Overall, global consumption is projected to rise by 50 percent between 2005 and 2030, mostly driven by fossil-fuel use [source: United States Energy Information Agency].

Let’s examine the key energy sources powering the world while accounting for those 15 terawatts. We’ll also look into some of the rising alternative, renewable energy options that are becoming more popular.

Global Energy Consumption

Around 43 percent of the global population relies on oil as their primary energy source, followed by 15 percent using natural gas. Combustible renewables and waste contribute 13 percent, coal 8 percent, and alternative sources such as geothermal, hydro, and solar make up percent [source: IEA].

Fossil fuels like gasoline, heating oil, and diesel are commonly used for energy, but petroleum products also serve other purposes. These materials are essential in making items such as crayons, plastics, tires, and even heart valves [source: Energy Information Administration]. This highlights how energy consumption extends beyond just fueling cars or paying electricity bills. When you purchase a box of crayons, you're also accounting for the energy spent on manufacturing, packaging, and shipping the product to your local store.

Despite the environmental consequences of fossil fuels -- most notably global warming -- the world continues to rely on them, consuming them at a rate 100,000 times faster than they are formed [source: Solar Energy International]. The use of fossil fuels in developing nations has surged by four times since 1970. For instance, China is the largest consumer of coal globally and the third-largest oil consumer. The Worldwatch Institute reports that if Chinese citizens consumed oil at the same rate as Americans, China would require 90 million barrels of oil per day. This amount surpasses the total daily global oil production by 11 million barrels, as seen in 2001 [source: Worldwatch Institute]. This projection has troubling implications -- what would happen if any nation, including China, developed a 90-million-barrel-per-day oil dependency?

Various groups suggest measures to curb fossil fuel use, ranging from imposing fees to advocating for cleaner energy generation. The Intergovernmental Panel on Climate Change (IPCC) proposes a fossil fuel tax, charging $20 to $50 per metric ton of CO2 produced by a nation to compensate for environmental damage caused by burning these fuels. The connection between global warming and energy consumption has led many experts to urge industrialized countries to reduce their demand and shift production methods, while also encouraging developing countries to adopt sustainable, renewable energy sources and energy-efficient technologies.

Shifting to renewable energy sources could have an immediate positive impact on the environment. Let's explore the various types of renewable energy and the potential benefits they offer.

Wind power is the fastest-growing renewable energy source. If we replaced one month's worth of fossil fuel consumption with 100 kWh of wind energy, it would be the equivalent of keeping your car off the road for 2,400 miles (3,862 km). A 1 kWh photovoltaic (solar electricity) system would prevent the mining of 150 pounds (60 kg) of coal, stop 300 pounds (136 kg) of CO2 (and NO and SO2) from entering the atmosphere, and save 105 gallons (397 liters) of water from being consumed [source: Solar Energy International].

While some alternative energy sources can be costly and out of reach for the average homeowner, solar water heaters offer a way for regular consumers to lower their carbon footprint. By switching from an electric water heater to a solar-powered one, long-term savings on electricity can help prevent more than 50 tons of CO2 emissions from being released into the environment [source: Solar Energy International].

There are sustainable and efficient methods to generate energy on individual, national, and global scales, but achieving such a transformation requires both motivation and financial investment.