By Joe Romm on March 20, 2014 at 10:30 am
This week, the world’s largest general scientific society, the American Association for the Advancement of Science, has issued an uncharacteristically blunt call to action on climate change. The must-read new report by the AAAS’s Climate Science Panel, “What We Know” has several simple messages:
We are as certain that humans are responsible for most recent climate change as we are that cigarettes kill:
Climate scientists agree: climate change is happening here and now. Based on well-established evidence, about 97% of climate scientists have concluded that human-caused climate change is happening….
The science linking human activities to climate change is analogous to the science linking smoking to lung and cardiovascular diseases. Physicians, cardiovascular scientists, public health experts and others all agree smoking causes cancer. And this consensus among the health community has convinced most Americans that the health risks from smoking are real. A similar consensus now exists among climate scientists, a consensus that maintains climate change is happening, and human activity is the cause.
What kind of change is already happening?
Average global temperature has increased by about 1.4˚F over the last 100 years. Sea level is rising, and some types of extreme events — such as heat waves and heavy precipitation events -– are happening more frequently. Recent scientific findings indicate that climate change is likely responsible for the increase in the intensity of many of these events in recent years.
What is the danger of continued inaction?
We are at risk of pushing our climate system toward abrupt, unpredictable, and potentially irreversible changes with highly damaging impacts….
We can think of this as sudden climate brake and steering failure where the problem and its consequences are no longer something we can control. In climate terms, abrupt change means change occurring over periods as short as decades or even years”
Why must we act now?
The sooner we act, the lower the risk and cost. And there is much we can do. Waiting to take action will inevitably increase costs, escalate risk, and foreclose options to address the risk. The CO2 we produce accumulates in Earth’s atmosphere for decades, centuries, and longer. It is not like pollution from smog or wastes in our lakes and rivers, where levels respond quickly to the effects of targeted policies.
When asked on the press call why the AAAS felt the need for providing the public and policymakers yet another climate report, Dr. James McCarthy, Harvard oceanography professor and former AAAS President, said “The public has been misinformed by a colossal disinformation campaign.” Scientists must speak out strongly and often because the subject is too important to leave to the disinformers.
McCarthy also made a point I thought was key:
The risk concept — the risk of inaction — this is something that really hasn’t been emphasized. And if you just think back 20 years or 10 years – what we imagined twenty years ago about loss of Artic sea ice – it was not thought to be anything that would be of concern in this century. Ten years later, roughly 2000, we knew that we were on a trajectory that couldn’t be anticipated. Ten years ago that same era it was not thought that Greenland would be losing ice dramatically in the next few decades, but within a few years we realized that was wrong.”
See also: What We Know — AAAS