Climate change is amplifying extreme weather events like hurricanes, heatwaves and other disasters.

What’s the first thing that comes to mind when you think of how best to prepare for this stuff?

Moving inland?

Stockpiling water?

Buying flood insurance?

Building stronger relationships might not be high on that list, but maybe it should be [INTRO] Many communities on Earth are at increasing risk of one or more of these disasters hitting home.

And researchers have found that who you know -- and who knows you -- is one of the biggest predictors of survival and community recovery after a disaster.

It comes down to something called resilience, which is a measure of how much shock a system can take before it becomes something fundamentally different.

Like how you can squeeze a rock for a long time before it turns into a diamond, or how you can drive lots of cars onto a bridge until at some point, it stops being a bridge.

We humans have typically tried to become more resilient to the impacts of climate change, like flooding...by building dams, restoring wetlands, and elevating buildings.

But communities are more than just physical spaces.

There’s a social component of resilience that’s just as important.

In the summer of 1995, Chicago was hot.

For five days in a row, temperatures shot up to 106˚F (41˚C).

It was also humid -- the heat index topped 120˚F (49˚C).

People who *had* air conditioners ran them non-stop, which overwhelmed the grid and shut off power to some 50,000 residents.

People without A/C tried to stay cool however they could, crowding beaches and opening more than 3,000 fire hydrants on city streets.

Chicago had a city-wide heat emergency plan that would have issued public advisories, set up areas where residents could stay cool, and had people check on elderly and isolated residents.

But they didn’t implement it because the mayor was on vacation, and city officials dismissed the rising temperatures AND rising danger.

By the end of the heat wave, more than 700 people had died.

Their bodies overflowed from the morgue, so the medical examiner had to store them in refrigerated trucks.

When sociologist Eric Klinenberg studied how different Chicago neighborhoods responded to the heat wave, most of what he saw initially didn’t surprise him.

Lots of people died in hyper-segregated communities with high rates of poverty and violent crime–things that might isolate residents from each other.

But there were exceptions.

In a few communities with those same characteristics, people survived at higher rates than some affluent neighborhoods across town.

That meant that those factors -- race, income, or crime rate -- were not enough to predict who lived and died in the heat wave.

Take two Chicago neighborhoods: Englewood and Auburn Gresham.

On paper these communities were very similar, but they fared very differently.

In Englewood, citizens died at a rate of 33 per 100,000 during the heatwave.

In Auburn Gresham, citizens died at a rate of only 3 per 100,000.

So what made the difference?

Relationships.

In Englewood, half of the population had moved away over the previous 30 years, and the neighborhood had been abandoned by businesses.

On the other hand, in Auburn Gresham, the population had stayed roughly the same, and local businesses continued to thrive.

As a result, residents knew their neighbors.

This led people to check on vulnerable residents during the heatwave, and ensure they were okay - just as they did every other day.

We know that climate change will lead to more extreme weather events, many of which will be disastrous for certain communities.

We can look to other disasters for examples of how relationships impact a community’s ability to bounce back.

In the year after Hurricane Katrina hit New Orleans, 31 percent of residents had returned to their same homes in flooded areas of the city.

But in the Vietnamese-American section of the city called Versailles, 80 percent of homes had been re-occupied.

Thanks to the tight knit social community that had formed there in the mid-1970s, residents banded together to return and help each other rebuild.

In Japan after the 2011 tsunami, communities with strong social networks saw fewer deaths than more disconnected areas.

This was in large part due to “horizontal social ties” -- the connections neighbors have with one another.

They knocked on doors in vulnerable areas, and escorted people -- sometimes even carrying them away from danger.

In coming years, we’ll see more cities invest in physical infrastructure to protect their communities from the effects of climate change.

But for every wetland restored or dam built, cities may also want to consider investing in tools that allow residents to create and maintain strong social ties - the relationships that were so important in Chicago, New Orleans, and Japan.

That means creating spaces for people to build community, like parks and libraries.

It also means smaller–but no less significant changes, like rebuilding sidewalks and replacing burnt out street lights so people feel safe walking in their communities.

The more that residents want to shop, play and work in their communities, the more connections they’ll build with other residents along the way.

If any community -- be it a city or rural area -- wants to be ready for the weird climate future that we all face, social resilience will be a key ingredient.

Because when the storm comes, the levee fails or the temperature rises, sometimes it’s your neighbors who will help you weather what’s to come.