The important point in this article is the fact of pointing out other factors affecting the climate than just CO2. When a theory claims that a certain factor (eg CO2) is the cause of a phenomenon being studied (warming), the scientist has an obligation not only to show that the factor is the cause, but also an obligation to rule out other factors that could be contributing. Dr Pielke is correct to show that human land use may be as important or even more so than CO2 in regional climate phenomena. This essential part of the scientific method is shockingly rare or non-existent in the literature supposedly attributing warming to human-sourced CO2.
The map of the 48 States is far from accurate. For example, a large part of the Midwest are States are named cow pasture. This includes Missouri, Iowa, and much of Minnesota which are actually used largely for row crops. Corn being the major crop. The time when almost every farmer had a few milk cows was disappearing 80 years ago in these states. Also, Nebraska is the number 2 producer of corn in the US. Thanks to irrigation. Also, Oklahoma, Kansas, South Dakota and North Dakota have been major wheat producers for over 80 years.
And for major cities in Florida with temperature records going back to the late 1800s, most of the record highs are still from the late 1920s, the 1930s and the early 1940s. While the cities with records only going back some approximate 75 years, manage a fair number of new highs in more recent years. What is going into the records now is at least questionable to me. For example, here not far South of downtown Orlando, FL, I experienced this February 3 straight days of freezing weathers, with Temperatures of 30, 31 and 32-degrees. This killed part of my fall garden planting and damaging a number of fruit trees in the neighborhood. Now if I look at past whether history for these same days the lowest temperature is said to be 36 degrees.
I believe I remember reading that the IPPC has to exclude the 1930s to make their forecast of increasing temperature projections work. Maybe this is correct use of Statistics, but in my use of Trends to forecast future events, I tried to use as much good history as I could obtain and used Regression to project the likely future events. Maybe it is different this time and we need to forget everything but the more recent past. However, if this were so why isn’t it being explained by those most certain about future temperatures.
The earth's climate results from the net between incoming solar power and outgoing power. The more that we replace reflective surfaces with absorbing surfaces, the more net warming we get, independent of CO2 (and vice versa). Roger illuminated this important factor in climate change. At a global level, increases in urban areas, deforestation, and increases in farm land can drive the earth's absorptivity in either direction.
A secondary aspect of the effects of land use is that it has been widely observed in urban and semi-urban areas that much of the warming has been an increase in night temperatures, rather than day temperatures. That is due to absorption of solar energy by the huge array of concrete and other structures during the day, and subsequent release at night. Urban areas are always warmer than surrounding suburbs because of the great concentration of human generated energy. I experience this every weekend when I drive from a suburban area in Orange County (CA) through downtown Los Angeles up to suburban Pasadena (CA). I leave OC in the morning at 48 F, reach a high in LA at 54 F, and return to about 48 in Pasadena. Many of the original temperature measurement sites in the grand network were originally placed at relatively remote sites that eventually became urbanized. A comparison of recent temperatures to temperatures decades ago is skewed by urban warming.
When the desert (solar absorption ~ 0.3) is covered with solar cells (solar absorption ~ 0.9)(they appear black) there is an increase in absorptivity of ~0.6. Desert sun during day is about 1 kW per square meter. A desert solar farm 5 km by 5 km absorbs 23 MW (megawatts) of solar power while bare desert would absorb about 7.5 MW of solar power. Of the 23 MW of solar power absorbed by the solar farm, about 5 MW is converted to electric power and 18 MW remains as additional heat in the desert. The solar farm actually warms the earth. The 5 MW of solar electric power also ends up as heat after usage. Thus, the solar farm adds 23 MW of absorbed solar power to the earth, whereas bare desert would add only 7.5 MW of absorbed solar power.
My experience, at least to my perception is that here in Orlando, FL as the city expanded into a significant heat island, humidity rose substantially. This increase in humidity associated with heat islands makes it actually more difficult to set new record highs as well as lows. Resulting in most of our cold temperature records being previous to 1920 when the city was much smaller. Also most of the record highs to be centered in the 1930s. Will these record high temperatures be broken by new highs, it remains to be seen. It's possible.
I find the use of the word “skillful” by climate scientists to be intriguing. In quantitative analysis we use the terms accuracy and precision to assess a process that measures some physical variable, such as temperature. Gavin Schmidt says, “Predictive skill is defined as the whether the model projection is better than you would have got assuming some reasonable null hypothesis.” A definition remarkable for its lack of quantification--- a skillful avoidance of the standard statistical measures of accuracy and precision, lol.
So, this is a very interesting article about using models to assess the impact of land use on climate. I’m not disparaging the usefulness of this approach at all. But, as you say, it mainly shows how computationally complex the climate is and why the IPCC range of ECS can’t be narrowed using models.
The main takeaway for me is that the intense focus on quantifying and mitigating CO2 hazard risk is of limited use. This is why Roger Jr.’s focus on policy is most crucial.
Excellent article! I'm glad someone has finally shown a light on this important driver of our climates that until recently has worked in the dark.
It also points out the irony that there is so much more anti-fossil fuel climate activism in those areas with the greatest alteration of the landscape.
One quibble and question re Florida.
• The graphic seems to show the actual area of FL, esp. S FL, as unchanged. I don't think that's actually true. This gives rise to a question.
• Subsidence apparently plays some role in the increase in the apparent sea level in SE FL (I can make a case for it being half of the observed SLR), and many other places. This has to do with - among other things - the "collapse" of some of the minerals underlying some of this area. The clays and other minerals interact with sea water and structurally are altered and compact. Of course, the overlying buildings play a role because of their weight. Has anyone tried to tease out the effect of the mineralogical changes on local climates? NOLA and Norfolk are important examples where subsidence is of major importance. Conversely, Alaska's coast is upwelling.
This was a very informative article. It supports the common sense notion that human land use impacts the regional climate as well as distant areas through teleconnection.
The human ability to modify the land has been enhanced through industrialization. Fossil fuels have provided most of the energy for the machines that do the work associated with land use. Petroleum and natural gas production has required minimal changes to the land itself. Coal production by mining, both underground and surface, has had a land use and environmental impact. But these negative effects are trending downward in the US due to improved practices and regulations.
That said, I wonder what the effect of biofuels, solar/wind farms, mineral extraction for batteries and declining agricultural productivity (due to limited fertilizer and non-GMO activism) will turn out to be. I suspect there will be some land modifications for more hydro energy and irrigation use. What bothers me is that I don’t think there is anyone looking at the big picture. Those that say they are may actually be captives of vested interests. The United Nations comes to mind.
Please revise the "cow pasture" designation of Midwest with something like row crops
The important point in this article is the fact of pointing out other factors affecting the climate than just CO2. When a theory claims that a certain factor (eg CO2) is the cause of a phenomenon being studied (warming), the scientist has an obligation not only to show that the factor is the cause, but also an obligation to rule out other factors that could be contributing. Dr Pielke is correct to show that human land use may be as important or even more so than CO2 in regional climate phenomena. This essential part of the scientific method is shockingly rare or non-existent in the literature supposedly attributing warming to human-sourced CO2.
The map of the 48 States is far from accurate. For example, a large part of the Midwest are States are named cow pasture. This includes Missouri, Iowa, and much of Minnesota which are actually used largely for row crops. Corn being the major crop. The time when almost every farmer had a few milk cows was disappearing 80 years ago in these states. Also, Nebraska is the number 2 producer of corn in the US. Thanks to irrigation. Also, Oklahoma, Kansas, South Dakota and North Dakota have been major wheat producers for over 80 years.
And for major cities in Florida with temperature records going back to the late 1800s, most of the record highs are still from the late 1920s, the 1930s and the early 1940s. While the cities with records only going back some approximate 75 years, manage a fair number of new highs in more recent years. What is going into the records now is at least questionable to me. For example, here not far South of downtown Orlando, FL, I experienced this February 3 straight days of freezing weathers, with Temperatures of 30, 31 and 32-degrees. This killed part of my fall garden planting and damaging a number of fruit trees in the neighborhood. Now if I look at past whether history for these same days the lowest temperature is said to be 36 degrees.
I believe I remember reading that the IPPC has to exclude the 1930s to make their forecast of increasing temperature projections work. Maybe this is correct use of Statistics, but in my use of Trends to forecast future events, I tried to use as much good history as I could obtain and used Regression to project the likely future events. Maybe it is different this time and we need to forget everything but the more recent past. However, if this were so why isn’t it being explained by those most certain about future temperatures.
Some perhaps irrelevant and irreverent views:
The earth's climate results from the net between incoming solar power and outgoing power. The more that we replace reflective surfaces with absorbing surfaces, the more net warming we get, independent of CO2 (and vice versa). Roger illuminated this important factor in climate change. At a global level, increases in urban areas, deforestation, and increases in farm land can drive the earth's absorptivity in either direction.
A secondary aspect of the effects of land use is that it has been widely observed in urban and semi-urban areas that much of the warming has been an increase in night temperatures, rather than day temperatures. That is due to absorption of solar energy by the huge array of concrete and other structures during the day, and subsequent release at night. Urban areas are always warmer than surrounding suburbs because of the great concentration of human generated energy. I experience this every weekend when I drive from a suburban area in Orange County (CA) through downtown Los Angeles up to suburban Pasadena (CA). I leave OC in the morning at 48 F, reach a high in LA at 54 F, and return to about 48 in Pasadena. Many of the original temperature measurement sites in the grand network were originally placed at relatively remote sites that eventually became urbanized. A comparison of recent temperatures to temperatures decades ago is skewed by urban warming.
When the desert (solar absorption ~ 0.3) is covered with solar cells (solar absorption ~ 0.9)(they appear black) there is an increase in absorptivity of ~0.6. Desert sun during day is about 1 kW per square meter. A desert solar farm 5 km by 5 km absorbs 23 MW (megawatts) of solar power while bare desert would absorb about 7.5 MW of solar power. Of the 23 MW of solar power absorbed by the solar farm, about 5 MW is converted to electric power and 18 MW remains as additional heat in the desert. The solar farm actually warms the earth. The 5 MW of solar electric power also ends up as heat after usage. Thus, the solar farm adds 23 MW of absorbed solar power to the earth, whereas bare desert would add only 7.5 MW of absorbed solar power.
My experience, at least to my perception is that here in Orlando, FL as the city expanded into a significant heat island, humidity rose substantially. This increase in humidity associated with heat islands makes it actually more difficult to set new record highs as well as lows. Resulting in most of our cold temperature records being previous to 1920 when the city was much smaller. Also most of the record highs to be centered in the 1930s. Will these record high temperatures be broken by new highs, it remains to be seen. It's possible.
I find the use of the word “skillful” by climate scientists to be intriguing. In quantitative analysis we use the terms accuracy and precision to assess a process that measures some physical variable, such as temperature. Gavin Schmidt says, “Predictive skill is defined as the whether the model projection is better than you would have got assuming some reasonable null hypothesis.” A definition remarkable for its lack of quantification--- a skillful avoidance of the standard statistical measures of accuracy and precision, lol.
So, this is a very interesting article about using models to assess the impact of land use on climate. I’m not disparaging the usefulness of this approach at all. But, as you say, it mainly shows how computationally complex the climate is and why the IPCC range of ECS can’t be narrowed using models.
The main takeaway for me is that the intense focus on quantifying and mitigating CO2 hazard risk is of limited use. This is why Roger Jr.’s focus on policy is most crucial.
Excellent article! I'm glad someone has finally shown a light on this important driver of our climates that until recently has worked in the dark.
It also points out the irony that there is so much more anti-fossil fuel climate activism in those areas with the greatest alteration of the landscape.
One quibble and question re Florida.
• The graphic seems to show the actual area of FL, esp. S FL, as unchanged. I don't think that's actually true. This gives rise to a question.
• Subsidence apparently plays some role in the increase in the apparent sea level in SE FL (I can make a case for it being half of the observed SLR), and many other places. This has to do with - among other things - the "collapse" of some of the minerals underlying some of this area. The clays and other minerals interact with sea water and structurally are altered and compact. Of course, the overlying buildings play a role because of their weight. Has anyone tried to tease out the effect of the mineralogical changes on local climates? NOLA and Norfolk are important examples where subsidence is of major importance. Conversely, Alaska's coast is upwelling.
This was a very informative article. It supports the common sense notion that human land use impacts the regional climate as well as distant areas through teleconnection.
The human ability to modify the land has been enhanced through industrialization. Fossil fuels have provided most of the energy for the machines that do the work associated with land use. Petroleum and natural gas production has required minimal changes to the land itself. Coal production by mining, both underground and surface, has had a land use and environmental impact. But these negative effects are trending downward in the US due to improved practices and regulations.
That said, I wonder what the effect of biofuels, solar/wind farms, mineral extraction for batteries and declining agricultural productivity (due to limited fertilizer and non-GMO activism) will turn out to be. I suspect there will be some land modifications for more hydro energy and irrigation use. What bothers me is that I don’t think there is anyone looking at the big picture. Those that say they are may actually be captives of vested interests. The United Nations comes to mind.
Great article Roger.