Urban Heat Islands

So it struck me the other day while winding through the country roads to Mt. Baker, that there is a potential fly in the ointment of a phenological calendar kept to record the effects of a changing climate as written in the trees, the birds, the bees... 

2008 marked the point in history where 50% of the world's human inhabitants could be classified as city-dwellers.  That percentage is only going to grow as a) these city-dwellers beget city-dwellers, and b) cities continue to extend their outskirts outward like the growth rings of a tree or the bands of a snail's shell.  Even as urban planners come to embrace the concept of building up rather than out, more and more forest and meadow is being substituted with asphalt and blacktop. 

Collectively, these paved surfaces absorb more of the sun's heat than the natural surfaces they replaced and as a result, the temperature of the immediate surroundings goes up - a phenomenon called 'the urban heat island effect'.  I was reminded of this today on the frisbee field while looking out over the turf & track and seeing the blurry heat waves radiating upward.  Even this mostly green 'field' (with its little black bits of chewed up tire) is contributing to Seattle's heat island.  This increase in temperature undoubtedly plays a role in determining bloom times within the urban landscape.  To my knowledge, this is a factor that is overlooked by citizen scientist groups such as the USA National Phenological Network mentioned in my previous post.

What are the implications of such an oversight, and does it devalue the work being done.  I think not.  It simply means that we need to look at the data through a more refined lens, a lens that takes into account the effects of the concrete jungle.  The world has moved into new territory, territory that more often than not has been altered in some way by human hands.  The phenological records accumulated over the centuries no longer fully apply, we need a new baseline.  As our population of urbanites grows, so too does our footprint upon this Earth.  And while I used to see our ever burgeoning numbers as the biggest obstacle to our survival, I now see it as our biggest opportunity. 

Our species has made so many mistakes since leaving our Mother's tender, loving and brutal care.  Her's is a tough love based on natural consequences, and it has kept the natural world in order for billions of years.  But in the 100,000 years that our kind has been around, we've stubbornly opted to forge our own way.  We've invented our own accounting system, and adopted our own set of rules to get to this point.   The mistakes we've made along the way are due in most part because we simply didn't know any better.  And while we've been bumbling through this existence with the swagger of a cowboy (embodied by our former president), we've also been learning and improving with every generation. To quote Mr. Vedder, "it's evolution, baby".  

We're even starting to learn humility as we tune our ears to the lessons of our ancestral home.  We're building our cities with an eye on sustainability.  The materials we're using are less harmfully extracted, and in many cases are reclaimed from past ventures.  We understand the value of greenspace as never before and demand that our communities include parks and buffers and tracts of pseudo wilderness.  Swamps have become wetlands, and they're no longer dumps or wastelands needing improvement but refuges, nurseries, and filters needing protection.  Rain barrels, solar panels, porous pavement, electric cars, green roofs...the list of innovations goes on and on. 

It's an exciting time to be alive, and what's most exciting to me is that the kids I meet these days totally 'get it'.  And as their numbers grow, so too does our pool of great ideas and our capacity to move mountains.  "Many hands make light work", and while the work in front of us is anything but light, we certainly do have many hands.  According to Nat Geo, swaths of forests the size of Panama are cut down each year, and if deforestation continues at it's current rate, there will be no forests left in 100 yrs.  This is tragic and must change, but think for a moment about all those hands across the world engaged in a re-forestation project. 

Earth Day is coming up blogosphere, the 40th anniversary if I'm not mistaken.  I challenge each and everyone of you to do as John Denver instructed and "plant a tree for your tomorrow".  I can think of no single action more powerful.  Trees suck up CO2 and store it away in something useful (wood), they oxygenate the planet, slow down storm water, provide habitat for animals jungle gyms for kids, fodder for poets, artists and scientists alike, and inspiration for romantics like me.  On top of all of these things, if you plant your tree in a city, it will help mitigate that heat island effect that started this rant.  And if you live in Seattle, the city will even provide the trees, check it out here.  Good luck and happy planting.