Earth is absorbing an energy imbalance equivalent to the energy of four hundred thousand (400,000) Hiroshima atomic bombs every day due to global warming, according to Dr. James Hansen, one of the world’s leading climate scientists. Speaking at the TED Conference in Long Beach, California a year ago, he explained that scientists have methods to measure the heat content in Earth’s heat reservoirs, such as the oceans, which are gaining heat at a substantial rate. Additionally, land at depths of tens of meters is warming rapidly. This has resulted in an energy imbalance of 0.60 watts per square meter, which is twenty times the rate of energy used by all humanity.
Dr. Hansen has been at the forefront of climate science since the 1980s, when he published an article in Science Magazine which was repeated on the front page of the New York Times. This article concluded that the observed warming of 0.4 degrees C the prior century was consistent with the greenhouse effect on increasing CO2 and predicted that Earth would likely warm in the 1980s, leading to shifting climate zones, drought-prone regions in North America and Asia, erosion of ice sheets, rising sea levels and the opening of the Northwest Passage – all of which have either happened or are well underway.
In the 1980s, Dr. James Hansen testified to Congress about the dangers of global warming, warning that heat waves and droughts would become more extreme, and that rainfall would become more intense, with stronger storms and greater flooding. Four decades later, his predictions have been borne out.
Dr. Hansen was Head of NASA Goddard Institute for Space Studies from 1981 to 2013. In 2004, he was told by high-ranking U.S. government officials to stop talking about the impact of human activity on the climate, as it was not understood what “dangerous” meant in this context. In 2006, he appeared on 60 Minutes, accusing the George W. Bush White House of editing climate-related press releases to play down the threats of global warming.
In 2013, Dr. Hansen left NASA to focus on educating the world about the dangers of climate change. He explains that adding CO2 to the atmosphere is like adding an extra blanket to a bed, reducing the amount of heat that radiates into space. The longer we wait to address the issue, the more difficult and expensive it becomes. If we had started in 2005, emissions would have needed to be reduced by 3% per year to restore planetary energy balance and stabilize the climate. If we start in 2013, emissions must be reduced by 6% per year, and if we wait another decade, the reduction must be 15%. Yet, as Dr. Hansen laments, “we are not even starting!”
Climate Change Denial
Dr. Hansen’s speech addressed the issue of climate deniers, and their claim that the Sun is the main cause of global warming. He countered this by pointing out that the current energy imbalance is occurring during the “deepest solar minimum on record when the Sun’s energy reaching Earth is least”. Deniers also argued that 800,000-year studies demonstrate that rising temperatures lead CO2 changes, by a few centuries, proving CO2 does not cause global warming. However, Dr. Hansen argued that the lag is exactly what science expects as CO2 is a feedback to rising temperatures in centuries past. Studies of the distant past show that ice sheets, CO2, and methane were feedbacks that amplified global temperature change, causing ancient climate oscillations to be huge.
Dr. Hansen’s main point was that the same amplifying feedbacks are occurring today, as Earth warms due to the CO2 we put into the atmosphere. Ice will melt and warming oceans and melting permafrost will release CO2 & methane, amplifying hotter temperatures, in the same way as in past millennia when slight tilts in Earth’s rotation caused identical conditions.
Current Conditions – Ripe for Big Trouble
Dr. Hansen has warned that the current climate conditions are a harbinger of serious climatic trouble. Data from the Gravity Recovery and Climate Experiment (GRACE) satellites, launched in 2002, reveal that both Greenland and Antarctica are losing mass at an accelerating rate. Furthermore, methane is beginning to escape from the permafrost, and the current CO2 reading of 397 parts per million (ppm) is higher than the 390 ppm at which sea levels were previously at least fifty feet higher. Unless corrective actions are taken, burning fossil fuels at the current rate could lead to a sea level rise of eighteen feet this century, a process which would be beyond humanity’s control. This would lead to the disintegration of ice sheets and the flooding of coastal cities, as well as the extinction of many species.
Recent heat waves across the world, such as the 2012 drought in the U.S., Russia’s two extreme droughts in the past four years, and India and Syria’s heat waves, are more than three times standard deviations. This is a stark contrast to fifty years ago, when such heat wave anomalies covered only 0.2% of the Earth’s surface, compared to today’s 10%. As a result, the world’s breadbaskets are increasingly at risk due to the more frequent and widespread droughts.
The Climate Problem is Destined to Persist
Every year, governments across the world provide subsidies of up to $500 billion to the discovery and production of fossil fuels. This is akin to launching a rocket into outer space to divert the trajectory of an incoming asteroid, yet we remain idle in the face of the consequences of our inaction. Dr. Hansen, a renowned scientist, has warned of the “tipping point” – a point of no return when the Earth has had enough of the effects of climate change and it is too late to take action.
Dr. Hansen began his career studying Venus, Earth’s “sister planet”, and has since been at the forefront of research into its atmosphere. Recent studies suggest that billions of years ago, Venus had a much more Earth-like atmosphere with significant amounts of water on its surface. However, the runaway greenhouse gases caused the water to evaporate, leaving the planet with a thick layer of carbon dioxide and an average temperature of 900 degrees Fahrenheit.
The same fate could befall Earth if we continue to rely on fossil fuels. The longer we wait to reduce emissions, the more difficult and expensive it becomes – a “fatal attraction” that could vaporize the planet’s precious water.
