Passing by a shop window recently, a giant photo of a young woman wearing an uncertain half-smile caught my eye. Emblazoned beneath her in meter-high letters were the words "the future is bright." A bold statement. In more ways than one. Yet for all the bellowing of the message, the look on the model's face seemed to quietly whisper a different story.

Maybe she knew she was posing for an untruth. For a future in which the most immediate brightness is cast by the orange glow of climate fires, in which temperatures soar and ice sheets continue to melt while fossil fuels are extracted and burned as if we knew no better; for a future in which drought and flooding compete for relief and hurricanes batter shores while politicians shrug it all off with reckless abandon.

Such realities, such devastating disassociation, are at the heart of today's global strike. Organized by international climate movement  Fridays for Future (FFF), it is another demand for ambitious goals and action, another attempt to drive home that simple truth that we really do only have one planet, and another reminder to critics who belittle FFF as a passing teenage phase, that nothing could be further from the truth.

Record-breaking temperatures meet deforestation

More than two years have passed since FFF founder Greta Thunberg embarked on her first solo strike outside the Swedish parliament. And a year has slipped by since the school strike movement that grew up around her mobilized at least 6 million people in 150 countries to demand climate action.

Much has happened in that time. Highest-ever temperature records have been broken, Siberia, Australia, the US have all experienced unprecedented fires connected to global heating, glaciers have continued to retreat, cyclones in Africa have claimed more than a thousand lives and drought has hit agriculture across much of Europe. Meanwhile, deforestation continues in the Amazon, US President Donald Trump has given the green light for oil and gas development in Alaska's Arctic refuge, and Germany is not planning to kick its coal habit until 2038.

Throughout it all, FFF activists have been pushing world leaders to act. Less visibly perhaps, as the pandemic forced them to protest online instead of gathering en masse, but they've continued applying pressure.

Over the past weeks and months alone, Thunberg has had an audience with European Commission President Ursula von der Leyen and with German Chancellor Angela Merkel. Prior to the pandemic, she and other FFF members had won a reputation for being unafraid to offer harsh truths to heads of state and industry at high-ranking events around the world.

New climate targets from China won't save the planet

Such meetings and appearances are freely dismissed as publicity stunts. On both sides. Yet cities, governments and even the EU have declared climate emergencies, and earlier this month, von der Leyen, who laid out a green deal for Europe at the end of 2019, said the bloc should now be aiming for a 55% cut in carbon emissions by 2030.

And just this week, China — the world's biggest CO2 polluter — announced plans to hit its own emissions peak in 2030 and become carbon neutral by 2060. The date stretches painfully into the distance, and the goal will not keep temperature rise below 1.5 degrees Celsius, but it is being regarded as a significant step along the global climate action path.

Politicians would be unlikely to hold up their hands and attribute big policy shifts to a group — albeit a big one — of teenagers and 20-somethings, but it's hard to imagine they haven't been touched by the influence and tenacity of this movement that has spawned countless sub-groups and proved itself difficult to ignore.

Friday's global strike will be different from that massive euphoric event this time last year in that it will be tailored to each location's COVID-19 restrictions, but it will be no less determined. As FFF participants say themselves, they will keep protesting as long as the exploitation of nature is allowed to continue. Until the climate crisis is overcome.

That, of course, will require bold, concerted action at a policy and regulatory level. It will require politicians the world over to be as tenacious in their actions as the teenagers calling for today's strike. If our heads of government, state and industry were to follow that lead, the future would assume on a whole new brightness. And that would be something worthy of a genuine smile.