Don't forget Land Use

A very good piece, How land use changes the climate by Roger Pielke Jr..  The subheading is Roger Pielke Sr. explains (SERIES: Pielke Sr., Part 2)

I have long argued that even without humans we would have global climate change owing to variations in solar activity, geological activity, ocean/cloud activity and dozens of lesser factors.  Of course climate changes.  The question is what are the drivers and to what extent are each of the contributors responsible.

Is CO2 a contributor?  Probably but the case is open.  Is CO2 the only driver of climate change (much less global warming)?  Certainly not.  

And if it is not the primary driver of climate change, just how much of a role does it play?  We don't know.  Maybe nothing.  Maybe 5%.  Possibly 10% but likely not much more.

This cannot be discussed with anthropogenic global warming fanatics because they cannot concede other contributors.  If CO2 is only potentially one among many drivers, then the cost-benefit justifications for their preferred policies, already weak, go out the window.

More interesting to me has been the willful avoidance of what I think is much more a clear driver of local climate change.  Land Use.  It is clear anecdotally and it is clear by the data.  Land use has a clear and material linkage to changes in local climate.  It is the easiest argument to win but there is no engagement with it.  It is not clear to me why not.

My speculation is that if you concede land use, then you take the focus off the coercive CO2 control policies and perhaps they are concerned that diffusion of focus might be defeating.  Alternatively, they might wish to avoid the debate because land use is so clearly tied to practical and real world consequences to people.  It is one thing to argue that people ought to pay 1% more in costs or taxes for a possible payoff a century from now.  As long as you keep your demands at least somewhat moderated, you have a chance of winning.  Nobody wants to waste time fighting bad policy, especially if the win has only a small savings.

It is a different thing altogether to ask a farming community to give up farming or a manufacturing community to give up manufacturing or an urban community to give up urban living.  You are almost guaranteed defeat.  You are an existential threat and therefore many if not most have an incentive to resist your policies.  

I don't know whether that is what is going on, I just know that land use seems to get very little coverage even though it is a greater and more certain impact on climate.  

Large-scale alterations to the land surface can affect the weather and climate. For example, changing the land surface can alter albedo (its reflectivity of solar radiation back into space) which directly alters sensible heat (heat that we can measure with a thermometer) and latent heat (which is in the form of water vapor) mixed into the atmosphere. 

There are many peer reviewed papers that have for decades convincingly shown that land use can change regional climate. For instance, Gordon Bonan, a climate scientist at the National Center for Atmospheric Research in Boulder, Colorado, explained the significance research that I led on the effects of land use on the weather and climate of south Florida:

“Nobody experiences the effect of a half a degree increase in global mean temperature. What we experience are the changes in the climate in the place where we live, and those changes might be large. Land cover change is as big an influence on regional and local climate and weather as doubled atmospheric carbon dioxide—perhaps even bigger….. Climate change is about more than a change in global temperature. It’s about changes in weather patterns across the Earth… The land is where we live. This research shows that the land itself exerts a first order [primary] influence on the climate we experience.”