New York needs to cease using fossil fuels immediately and move toward renewable sources of energy in order to limit the inevitable impact of climate change, experts said in response to the latest United Nations climate change report.

The report’s predictions for low-lying coastal cities like New York City are grim: more deadly heat waves and sea level rise that could render parts of Lower Manhattan uninhabitable in this generation if no action is taken to limit global warming.

“You’re going to have to move faster – every city is going to have to move faster,” said Tim Kohler, an archaeology and evolutionary anthropology professor at Washington State University and one of the lead authors for the North American section of the report. “We’re putting greenhouse gasses into the atmosphere and that has to stop or places like New York City are going to have huge problems.”

The assessment was released Monday by the Intergovernmental Panel on Climate Change (IPCC). Representatives from 195 UN member countries met over the last two weeks to come to a consensus on how global warming is influencing nature, agriculture and human health. The report also gives lawmakers a roadmap on the potential and limits for humans to adapt to these changes.

Their message to the world is clear: the time to act is now, or low-lying coastal cities like New York City, who are at the highest risk, can expect a future fraught with even hotter temperatures and more flooding from sea level rise, intense storms and increased rainfall.

This assessment is the sixth made by the panel — it leaves no doubt that the planet is at its tipping point, and some of the fallout is already irreversible. Even with a scenario of substantially reduced greenhouse gas emissions, the odds are now greater than 50% that global warming will approach or surpass 1.5 degrees Celsius by 2040, according to the IPCC report. The planet is already, on average, 1.1 degrees Celsius warmer than 1850-1900 levels and is on pace to reach 2 degrees or more, according to Kohler.

“If we took the most aggressive possible action all over the world, it’s unlikely that we could do better than stop global warming at 1.5 degrees Celsius,” said Kohler. “That’s very dicey ground because frankly it becomes hard to predict exactly what will happen when temperatures get that high.”

Breezy Point, Queens, in November 2012, after Hurricane Sandy made landfall.

For the New York metropolitan area, the climate forecast involves longer, hotter and more frequent heat waves, and the report lays out how these changes would affect human physical and mental health. Over the past decade, on average, New York City experienced an estimated 350 heat-related deaths every year. These deaths are two times higher among Black residents.

The IPCC report explains how these patterns will worsen over time, affecting how often humans can be outside for work or recreation because the temperatures would be too hot to tolerate. This is a serious concern for New York, which experiences the urban heat island effect. The very stuff that forms the urban landscape – concrete and asphalt – is heat absorbent and can raise daytime temperature by up to 7 degrees Fahrenheit, and by up to 5 degrees in the evening. The effects are worse in lower income neighborhoods because of lack of greenspace as a result of structural racism in housing and infrastructure development. Planting as many trees as possible, expanding parks and maximizing green roofs are very effective ways to combat the increased heat, Kohler said.

Even limiting global warming to a best case scenario of 1.5 degrees Celsius warmer would still cause irreparable harm. Sea levels in the metropolitan area have risen by almost 9 inches since 1950, and the pace is accelerating — increasing by 1 inch every seven to eight years. Currently, 120 square miles of New York City is only 6 feet above high tide, making it prone to storm flooding. These areas are home to nearly a half-million people, 1,500 miles of road, 100 public schools — all estimated at more than $100 billion in value, according to the research organization Climate Central. Hurricane Sandy’s highest flood level was measured at 9 feet above the high tide in 2012.

Extreme flooding is estimated to increase by about 20% if sea levels rise roughly 6 inches more than 2020 levels by 2040, according to the IPCC report. This fallout doubles if seas rise to nearly 2.5 feet more. Daniel Van Abs, professor of practice for water, society and environment at Rutgers University, predicts at least an increase of 1 foot by 2050.

“Storms have become much bigger,” said Van Abs, who was not affiliated with the IPCC report. “Basically sea level rise turns a moderate storm into a disaster because the water penetrates so much farther inland.”

In addition to parts of Lower Manhattan being uninhabitable as sea levels rise, subway, sewer and ferry networks would also be affected.

This flooding would be exacerbated by the increased frequency and intensity of storms. Last year, the city had three major storms, including the remnants of Hurricane Ida which caused record-breaking rainfall, resulting in at least 13 deaths and brought subways to a halt. The cost of the damage was tens of billions of dollars.

Queens residents pump water from their basement after being inundated from remnants of Hurricane Ida, September 2nd, 2021

In combination with the rise in sea level, future storms could mean getting swamped whenever there is moderate to heavy rain. With all the city’s power plants located in storm surge zones, that could mean a loss of power.

Wastewater treatment systems could be compromised, too. When the sea level rises, the salt water destroys pumps and electrical parts of treatment plants. Sewage backup, such as what was experienced during Ida, could become a regular occurrence in pipes, which are usually located right at sea level, causing sewage backups and floods.

“For several days after [Hurricane Sandy], we put a lot of sewage back into the harbor,” Van Abs said. “It’s very damaging and expensive to recover from.”

Climate change impacts upstate and elsewhere will influence the five boroughs, too. The city gets its supply of drinking water from as far as 125 miles away, from the Catskills and Delaware watersheds. While the region is experiencing heavy rainfall, Van Abs said there are also more dry spells, which means water is being supplied in concentrated bursts.

Brief, but heavy precipitation is not necessarily good for plants because most of the rain runs off and does not penetrate into the ground where it’s needed. Coupled with the increased disease and pests from shorter cold seasons, these patterns can reduce local food production, which is not anywhere near meeting the region’s demands, according to Van Abs. The tristate area is dependent on the western half of the country for food, which is experiencing drought and wildfires.

“New Jersey is called the Garden State,” Van Abs said. “What’s our number one crop – turf grass. We don’t eat that.”

Climate change needs to be central to all the decision-making we do from here on out.
Pamela McElwee, human ecology professor, Rutgers University

While New York City is considered a leader in climate change policy, Kohler said it’s not enough. The biggest steps New York can take, according to experts, is to cease using fossil fuels immediately for transportation and power generation and move toward renewable sources of energy.

But these choices are often in the hands of lawmakers, and they are often constricted by the price tag, according to Pamela McElwee, a human ecology professor at Rutgers University —the longer they wait, the more exponential the cost in dollars, human lives and ecosystems.

Climate change has a profound impact on the economy, McElwee said. Inflation and supply chain disruptions are a consequence of climate change. When it’s too hot outside, laborers can’t build homes. Storm flooding costs the city billions of dollars. Transportation and shipping is disrupted. For New York, a city that must import its basic necessities, those interruptions in supplies can be life-threatening and detrimental to its economy.

“Climate change needs to be central to all the decision-making we do from here on out,” said McElwee, who was not affiliated with this IPCC report. “It literally affects everything we do in every sector of our lives, and we ought to treat it as such and make policies as such.”

Although the IPCC report is meant for policy and decision-makers, Kohler said its findings are useful for individuals too, particularly the frequently asked questions portion that follows each section of the report. He said that each human can have an impact on mitigating climate change simply by not commuting to work and minimizing air travel.

“We can’t let up pressure because otherwise we’re going to be caught flat-footed,” Kohler said. “And our children and our grandchildren will regret that we didn’t do more when we had the chance.”