The latest international assessment of climate change, the Sixth Assessment Report (AR6) of the UN’s Intergovernmental Panel on Climate Change (IPCC), has been out for a week now. It further strengthens what other assessments have already been telling us for well over a decade: Climate change is happening now and it is happening throughout the world.
This has been the warmest decade on record, but surface temperature is just one of many indicators of our changing climate. Certain types of extreme weather events – such as heatwaves and heavy precipitation – are increasing in severity and frequency, leading to droughts in some locations and floods in others. Sea levels are rising as the oceans warm and land ice melts. We can see these changes play out in the news all the time – whether through wildfires in the American west or flooding in Germany.
Observations show that the climate is changing about ten times more rapidly than natural changes in climate based on paleoclimatic observations of the changes that occurred since the end of the last ice age. The evidence is clear that the climate changes over the last half-century are primarily due to the burning of fossil fuels in tandem with the clearing of forests and other land-use changes.
Natural mechanisms cannot explain the observed changes in climate. Natural factors such as changes in the energy output of the Sun have affected climate in the past; but over the last century, human activities have become the dominant influence on our climate. The science tells us that climate change is a very real and alarming issue that all Americans – and all people around the world – should be concerned about. The science tells us there is an urgent need to respond.
Almost as soon as the IPCC report was released, the denialists, whose only purpose seems to be to prevent action to respond to climate change, put out their usual misinformation and overstatements about remaining uncertainties. Being skeptical is part of science, but their misrepresentations, half-truths, and downright lies are not based on facts and reflect a lack of ethics. If this wasn’t such a serious issue, some of their statements would be almost laughable. The old red herring, “climate is always changing,” keeps appearing, but the real problem is that the rate at which humans are currently changing the climate is unprecedented in at least 2000 years. Other misrepresentations include the suggestion that the rate of sea level rise is not increasing, whereas observations clearly show it is accelerating.
Why should you believe the IPCC? First, their authorship represents the best scientists in the world studying the Earth’s climate. Second, the findings of the IPCC assessments are in strong agreement with other major analyses of the changing climate, including the U.S. National Climate Assessments (which are required by Congress) and assessments led by the U.S. National Academy of Sciences. And lastly, IPCC, despite some of the rhetoric in the media, is a sustained source for unbiased and highly relevant information on climate past, present, and future. The unbiased character derives from the fact that all nations jointly contribute to the IPCC, and it hence eschews politicization. The authors are chosen for their science, not their politics.
So, is there any hope? I think so. We can slow climate change and reduce its magnitude, but it will take a concerted worldwide effort to greatly reduce the human-related emissions that are driving these changes. The IPCC assessment shows that to limit warming to 1.5 degrees Celsius and avoid widespread catastrophic damage, carbon emissions need to be cut by half in the next 10 years and largely eliminated by 2050. All nations need to significantly transition away from emissions associated with fossil fuels and they also need to be more proactive in protecting their forests and other natural resources because of their importance in storing carbon. A variety of analyses show this can be done without harming the economy.
The reduction in U.S. emissions over the last decade, largely a result of our transition from coal to natural gas, another fossil fuel, is insufficient to achieve what is needed. And just because emissions in some countries have been increasing does not let us off the hook. Some of the solutions already being discussed include:
Advancing solar energy, storage, and wind power development, which creates jobs and spurs economic growth while avoiding carbon pollution.
Improving energy efficiency, which is the best, fastest, and cheapest climate change solution while saving consumers money on their utility bills, creating new installation and retrofit jobs.
Accelerating production of clean electric and alternative fuel vehicles, and modern higher-speed rail and better transit, to avoid carbon pollution while increasing mobility options, reducing air pollution, and creating transportation industry jobs of the future.
Investing in carbon dioxide removal and protecting our forests, that could pull carbon pollution back out of the atmosphere and help restore our climate.
Along with reducing the emissions driving climate change, efforts for adaptation and resiliency are crucial to planning for our future. New technology and capabilities developed here can lead the way for the rest of the world.
The infrastructure bill currently being considered by Congress is a step in the right direction. It has incentives for the transition of our energy and transportation systems, but it will not achieve as much change as needed if we are going to follow the narrow pathway available for securing our future. Binding agreements by all nations, perhaps through increased ambition by all countries and major updates to the Paris Agreement, are needed if we are really going to prevent significantly larger changes in climate and the impacts that would result.
The clock is ticking. We need to face the challenges of addressing our changing climate. The phony “debate” about the science needs to be transformed into a real debate about the solutions and supporting timely actions. Meaningful solutions rest on technological, educational, social, and cultural actions. We need to come together to address what is clearly the biggest challenge of our time.