Climate, explained warmly.

When we talk about extreme heat, we're not just talking about uncomfortable summers. We're talking about a physiological threshold — the point at which the human body can no longer cool itself, no matter what it does.

Wet-bulb temperature is the number that matters. It accounts for both heat and humidity. Above a wet-bulb temperature of 35°C (95°F), a healthy adult sitting in the shade with unlimited water will die within hours. We've already recorded conditions approaching that threshold in parts of South Asia and the Persian Gulf.

The people who die in heat waves are disproportionately elderly, poor, and living in cities. They're in apartments without air conditioning. They're working outside because they have to. They're in neighborhoods with less tree cover, more pavement, more heat-absorbing surfaces. This is not random. It is a pattern.

What can we do? Cooling centers work. Tree canopy works. Urban planning that prioritizes shade and green space works. Early warning systems work. These are not complicated interventions. They require political will and money directed toward the people most at risk.

Extreme heat is solvable at the local level in ways that climate change broadly is not. That's worth holding onto.

El Niño is a natural climate pattern. It happens when warm water that normally pools in the western Pacific sloshes eastward toward South America. That shift changes where heat and moisture move through the atmosphere, which changes rainfall, drought, and temperature patterns across the globe.

During an El Niño year, parts of the American Southwest get wetter. Parts of Australia and Southeast Asia get drier. The Atlantic hurricane season tends to quiet down. The global average temperature ticks up — sometimes significantly — because all that warm ocean water is releasing heat into the atmosphere.

Here's the part that matters right now: El Niño doesn't cause climate change, but it interacts with it. A strong El Niño on top of a warming baseline means record-breaking temperatures that would have been impossible in a cooler world. The records we've been breaking in recent years aren't just El Niño. They're El Niño plus decades of accumulated warming.

Part of my doctoral research at Scripps touched on this interaction — specifically how climate variability patterns like El Niño shape the extremes we're projecting forward. The signal of human-caused warming doesn't emerge cleanly from the noise of natural variation. Understanding that noise is part of understanding the signal.

When you hear 'El Niño year,' think: amplifier. It takes what's already there and turns it up.

A marine heatwave is not a gradual warming. It's a sudden, sustained spike — ocean temperatures running significantly above normal for days, weeks, sometimes months. The ocean has been quietly absorbing over 90% of the excess heat trapped by greenhouse gases. Marine heatwaves are what it looks like when that heat concentrates and surfaces.

I was part of a research cohort studying the next generation of marine heatwave science — what we know, what we're still learning, and where the field needs to go. One of the things that became clear: these events don't stay in the water. They reach into the atmosphere. They modulate temperatures over land. They influence hurricane intensity and tracks. They affect monsoon precipitation patterns in ways that reshape rainfall for entire regions. The ocean and the atmosphere are one system. What happens in one shows up in the other.

Marine heatwaves bleach coral reefs — sometimes killing them outright. They collapse kelp forests. They displace fish populations that coastal communities have depended on for generations. They disrupt the base of the marine food web in ways that ripple upward. These are not abstract losses. They are losses of food, of livelihood, of ecosystems that took thousands of years to build.

The frequency and intensity of marine heatwaves has increased dramatically in recent decades. That trend is expected to continue. But here's what I want you to hold: the science is advancing fast. Researchers around the world are building better early warning systems, better models, better understanding of how these events cascade. We are not helpless. We are learning.

The ocean is not a passive backdrop to climate change. It is a central character. And it is telling us something.

I want to talk about two things that are happening at the same time, and how they're both making it harder to stay grounded in what's real.

The first is the language of emergency. "State of emergency." "Climate catastrophe." "Uninhabitable Earth." These headlines are not wrong, exactly — the situation is serious. But the way they're framed often produces panic rather than clarity. Panic is not the same as urgency. Panic makes people freeze, disengage, or reach for the nearest distraction. It severs the connection between knowing something and being able to act on it. When every headline is a five-alarm fire, people stop being able to tell what actually requires their attention right now.

The second thing is the more blatant denial — the claim that climate change isn't real, isn't happening, isn't caused by humans. I want to be direct: climate change is real. It is happening. It is evolving before our eyes, in real time, in ways that scientists predicted decades ago. The evidence is not ambiguous. The science is not contested among people who study it. What gets contested is the policy response — and that disagreement gets manufactured into doubt about the underlying science itself. Don't let that sleight of hand work on you.

There's also a subtler version of this: the disconnection from nature that makes it easier to dismiss what's happening. Many of us live in ways that insulate us from the rhythms of the natural world — from seasons, from weather, from the ocean and the land. That distance is real, and it's been cultivated. It makes it easier to treat climate as an abstraction rather than something happening to a living system we are part of.

What I'd ask is this: follow authentic climate scientists. Not the loudest voices. Not the ones performing despair or performing certainty they don't have. The ones who tell you the truth and stay in the room with you. The ones who are rooted in hope — not because everything is fine, but because they believe people are worth telling the truth to. We need everyone. That includes you.