Our Planet II’s second hour looks at the life of bees — and polar bears — and tells us more about a changing climate

Our planet, David Attenborough reminds us in the opening moments of Following the Sun, Our Planet II’s second-of-four hour-long episodes, is solar powered.

It takes eight minutes for the sun’s rays to reach the Earth’s surface. Due to our planet’s tilt, they don’t reach its surface evenly, however. The solar energy arrives unevenly at different times of the year, depending on where it falls. And therein lies the key — if there is a key to be found — to understanding the changing climate, perhaps enough to delay and possibly even reverse the effects of what’s looking more like a climate emergency with each passing day.

Our Planet II’s second act focuses on the summer months, which in the Northern Hemisphere signal a wave of wildlife migrations, from wildebeest searching for grass on the plains of East Africa to snow geese taking to the skies in search of breeding grounds across the far reaches of northern Canada.

This is the time of year when honey bees are at their most active — to make just half a kg of honey, a colony of bees must fly 90,000 km — and pollinate more than a million flowers.

In just one hive, as many as 60,000 bees can work together as one superorganism. A healthy queen can lay an egg every 30 seconds; another 40,000 bees may be developing in this one hive alone.

There isn’t enough room for them all, so the hive inevitably splits. When their numbers reach critical mass, they begin to swarm. They must find a new home.

To a bee, home is a tree hole with the right size, height, and angle to the sun. No sun — no life.

Bees can only move like this when the sun’s energy provides them with enough food to rebuild their colony from its beginnings — and where there are suitable homing grounds, in which to find a suitable home.

The world is changing, and today’s nature programs — at least, those programs with a burning need to impart some valuable, useful message rather than just family entertainment — can be hard to watch at times.

Survival is hard at the best of times, and our mere presence, let alone what we have done to the planet already, has made the challenge of survival that much harder.

There’s a wrenching sequence late in Following the Sun, where a polar bear mother is leading her two cubs up a sheer rock face after a long swim over open ocean where once there would have been floes of ice on which to rest. One of the cubs, the stronger and larger of the two, follows its mother easily enough, but the second, smaller cub, weakened from a long, overextended swim, is falling behind. A wrong turn, a foot slip, could mean a 15-meter fall onto the rocks below. Panicking, he begins to cry out plaintively and heads in the wrong direction. His survival depends on staying close to his mother — if he can’t keep up, she will be forced to abandon him. Spoiler alert: He makes it.

The message is plain, though, for all but the most stone-hearted viewers: With a long journey ahead, and another long swim, he may not make it. With summer sea ice melting earlier than we’ve ever known, polar bears must spend more of their year swimming.

For animals used to traveling across ice, these changes may well prove to be too great.

Life often finds a way — that is the way of the natural world. Animals adapt; the most adaptable survive.

The climate is changing, though. The future, today more than at any point in recorded history, looks increasingly uncertain.

Next: a look at episode 3, The Next Generation