American Geophysical Union Issues Stark Warning on Climate Change

Yes, another scientific society has once again issued another urgent call to act on climate change. But lest we glaze over from an overdose of expert – and sometimes conflicting – climate statements, let me review with you some excellent guidance from a leading evangelical Christian denomination.

Last year, the Christian Reformed Church adopted a sweeping declaration and call to action regarding the threat of manmade climate change and its impact on vulnerable communities. Recognizing that churches hear many voices both endorsing and disputing mainstream climate science, they addressed the core question: Whom do we believe?

Their answer was both measured and thoughtful. But at its core was the distinction between individual debaters on the one hand, and consensus reports from established scientific societies on the other: “When a broad community of experienced and reliable experts, utilizing the checks and balances implicit in scientific review, agrees on consistent conclusions over a period of several decades, it is reasonable to accept these broadly based conclusions and plan for the future” CRCNA Report, p. 39.

Earlier this week, the world heard one of its largest and most respected scientific societies issue an unequivocal warning about the danger of climate change, and mankind’s obligation to act to mitigate the harm. The American Geophysical Union (AGU) issued a statement titled “Human-induced Climate Change Requires Urgent Action,” declaring that “humanity is the major influence on the global climate change observed over the past 50 years” and that “rapid societal responses can significantly lessen negative outcomes.”


“Human activities are changing Earth’s climate,” they said in the clearest layman-ready language to date.  “Human-caused increases in greenhouse gases are responsible for most of the observed global average surface warming of roughly 0.8°C (1.5°F) over the past 140 years. Because natural processes cannot quickly remove some of these gases (notably carbon dioxide) from the atmosphere, our past, present, and future emissions will influence the climate system for millennia.”

The AGU statement cited independent research from its members indicating increases in global air and sea temperatures, sea level, and atmospheric water vapor; and decreases in the extent of mountain glaciers, snow cover, permafrost, and Arctic sea ice.

“These changes,” they wrote, “are broadly consistent with long-understood physics and predictions of how the climate system is expected to respond to human-caused increases in greenhouse gases. The changes are inconsistent with explanations of climate change that rely on known natural influences.”

Their report came with a stern warning for the future: that global temperatures will continue to rise, and that the amount of warming will be determined by the level of greenhouse gases that we continue to emit. “Higher emissions of greenhouse gases will lead to larger warming,” said the report, “and greater risks to society and ecosystems. Some additional warming is unavoidable due to past emissions.”

And if “warming” sounds a bit benign, the AGU warned of a host of related ills, both now and in the future. These include more extreme weather, including severe heat, rainfall and coastal high water; threats to public health, water availability, agricultural productivity, and coastal infrastructure; and accelerated extinction of species due to both climate change and acidification of the oceans, which is a direct result of increasing carbon dioxide levels.

In a departure from typical scientific statements, the AGU took the further step of urging us to do something about manmade climatic disruptions. “Actions that could diminish the threats posed by climate change to society and ecosystems include substantial emissions cuts to reduce the magnitude of climate change, as well as preparing for changes that are now unavoidable.”

Faced with mounting evidence as to the sheer scale of the climate crisis that we face, scientific groups everywhere are speaking up with greater clarity and urgency. The U.S. National Academy of Sciences has pulled no punches in warning of extreme drought and flooding; inundation of coastal cities like New York, Miami and New Orleans; a doubling of wildfires or worse; and the extinction of many more species. The National Academies of the G8 countries have signed a letter urging prompt climate action, joined by China, Brazil, India, Russia, Mexico and South Africa. And 200 evangelical scientists have just written to Congress with the message that the “changing climate threatens the health, security, and well-being of millions of people who are made in God’s image,” and urging the passage of meaningful legislation to reduce carbon emissions.

But the AGU statement points up the wisdom of the Christian Reformed Church in their deliberations. “Scientists too are human,” they said. “Scientific conclusions may also contain error, exaggeration, or misstatement. As imperfect humans, this is unavoidable.” And that’s why the CRC particularly looks to consensus statements by respected groups like the AGU, rather than individual comments. “Broad support within a respected and knowledgeable community should convey high credibility to their position,” said their declaration.

In the case of the 61,000-member AGU, there was a dissenting voice. One member of the report panel, Roger Pielke Sr. of Colorado State is widely thought of as a climate skeptic or climate denier. And he has loudly declared his dissent, and even drafted his own version of the report, twice as long as the actual one, and suggesting only murky doubts and conflicting evidence about the reality of climate change. Of course, Pielke will get the lion’s share of the attention from certain news outlets, even though the AGU statement has been approved by the other 14 members of the report panel.

So, whom do we believe? The Christian Reformed Church would remind us to keep our eye on the dog, and not that wagging tail. And that’s because information is never absolutely perfect, but inaction can also be fatal. “Delay also carries risk,” said the CRC declaration, “and when significant impacts are very likely, it is no longer sufficient to watch and wait.”

We owe a debt of gratitude to the American Geophysical Union for their unequivocal warning about the consequences of climate inaction. And let’s not forget the Christian Reformed Church, for reminding us how to assess the credibility of conflicting voices in the cacophony that surrounds climate policy in America.

Thanks for reading, and may God bless you.

J. Elwood

For the full text of the American Geophysical Union Climate Report, please click here.

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