Wednesday, October 11, 2017

Shining a Light on Roof Solar Panels

Unless individuals make a move, energy alternatives will remain a bit player in addressing the challenges from fossil fuel emissions.  So, we decided to take the leap of roof solar panel installation for our home in Michigan.

Want to see how we're doing: ?

Step 1.  Plans and Contract

Research into solar powering our house started with an online search, followed by an expensive, out-of-state bid in 2016 and a more moderate bid from a Michigan company in early 2017.  Some email exchanges and then a formal proposal that was based on Google Earth imagery of our home (picture below; North is up).  No home visit occurred until later.

The bid is based on one year of electricity use, which, in our case, includes an outdoor hot tub (winter), A/C (summer), electric cooking and baking, but not requiring electric heating of water and air (besides well pump and furnace fan).  The calculation includes efficiency from SSE roof orientation and sun days, resulting in the installation of 30 panels that each can deliver 295W peak.  The total production represent ~100% of our electricity use on a full year basis.  Obviously, more electricity is generated in Summer when the Sun shines for more hours than in Michigan's Winter, while electricity use is inversely proportional to the seasons. Winter days are also affected by sun angle, which is much lower than summer, further limiting unimpeded panel illumination. 
The year calculation is below.

Our local energy company (DTE) only offers an energy credit structure for consumer electricity generation.  This is a key piece to consider before going this route.  Will the company offer energy credit as kWh during summer excess generation for winter use?  Does the company pay for excess energy?  The latter sounds good, but remember that they'll offer less per unit than they charge, and that they may require a long term lock-in rate that does not increase.  The latter is simply a bad deal.

On our area, DTE is an energy credit company, which guides the decision to install panels with power generation that about match our yearly usage.  In fact, the power company approves the maximum installation with this requirement.  Disappointingly, no incentives, credits or benefits are offered by town or state.  Luckily, a federal credit is available, which covers a substantial 30% of the full costs of installation.  Two nice gentlemen from Michigan Solar Solutions ( visited the house for roof and electrical panel inspection, and, after signing some paperwork, left with the down payment that started the process.

Step 2.  Approvals

It took 4 weeks to get approvals in place before installation.  Power company (Detroit Edison), city and township, even the county got involved.  Never seen that many interested parties and rules.  The power company was swift and supporting.  The civic approvals seem to focus on footprint and engineering specs.  The latter reflect the ability of the roof to carry the added load of solar panels, which should be ok for a typical home, and aesthetics.  A final building inspection took another week after panel installation, followed by the energy company's changeover another 2 weeks later.  Quite a few folks visited along the way.

Step 3.  Installation

Electricians and roof installers arrived around 8am and panels were delivered shortly thereafter.  The installation requires two vacant breakers on the breaker panel to connect with a controller unit outside.  This controller, in turn, connects with an inverter on each panel, requiring the installation of a thick wire tube outside the house.  That took about 3-4 hours.  Meanwhile roof workers installed racks to hold the 30 panels.  The panels are connected serial-like, allowing for replacement and additional panels.  A final outdoor switch was installed that cuts the system from the power company meter, as required, and shuts down the panels.  By 5 pm all panels and boxes were installed and running.  Drone camera images are below (courtesy of Jamal Hassunizadeh).

Running does not mean ready for use, however, as electrical and building inspections, and power meter changes are still needed.  The first two took another week and the meter change another 2 weeks.  Meanwhile precious late summer photons remained unused.  The inspections went smoothly.  Lastly the power company guy appeared on Friday afternoon at 5pm (after a couple of phone calls) to reprogram their meter to bi-directional metering.  Then the switch was permanently thrown.

Step 4. On

Remote power monitoring offers addictive opportunity for owners.  Weather has an entirely new dimension and clouds are cursed.  It is clear why they are called solar panels, and not light panels. The gentleman from Michigan Solar Solutions returned for their final payment a couple of days after the system went live.

Power and Energy

Energy is the ability to do work.  The unit is Watt-hour, meaning one Watt of electrical power, maintained for one hour: 1 Wh of energy.  Power means how fast the energy can be used, so it is energy over time; the unit is, thus, Watt.  A 30W lightbulb describes power, while energy consumed is a function of the time one uses that power.  Running a 30W bulb for 2 hours means 30*2=60Wh.  Have a look at this site for more explanation:

Today, our system of 30 panels is, for example, producing 5.5 kW, with an installed max of (30*295=) 8.85kW. In one day, it produces, say 30 kWh, which well exceeds our average use, but not by much. On a dreary and foggy day, the panels are producing a few hundred W only.  As the fog dissolves, this quickly moved into kW, peaking in the middle of the day when the sun is at its maximum.  Below is an annotated example record from the last 2 weeks of September.  Power generation should vary by season, peaking in late spring and summer.

A few surprises

Living in an area with frequent power outages, the panels will not supply energy to the home when the electricity grid is down.  This has to do, I was told, with frequency variations from consumer-grade generators and converter panel electronics that require active lines outside the house.  Glad we kept the generator for more than just nightime outages.  When, in the future, reasonably-priced batteries become available, the panels will be able to power the house without grid connection, after additional rewiring of charged batteries.  Note to Elon Musk: hurry up.

Installation of panels and electrical wiring took a day, but approvals and inspections drag on.  It took >8 weeks from signing the contract to operating the system.  The key step, energy company switch to solar metering, took another 2 weeks after all installation and inspections were done.  These permissions and visit scheduling alone are reasons to use a licensed contractor instead of managing installation oneself.

After a week the system went down (see image above).  A visit by the installer the next morning (quick response!) confirmed my suspicion that the problem was the home breaker box.  Ironically, the only part not new was the culprit, and an easy fix.

What about cost?

I am not sharing the actual cost of our installation, as this varies by size and region (and is nobody's business), but, based on our yearly electricity use and kW/h rate of DTE, we should see a positive return on investment after 10-12 years.  Clearly, this is not an investment strategy, but a moral choice.  The investment return calculation does not include price increases in electricity delivery (shorter return years), nor income loss from interest/investment of the money, or non-warranty repairs (longer return years).  Warranty should cover any malfunction for 6-10 years (depending on item), except for natural events like falling branches/trees, wind and hail, which are under the home insurance (with deductible).  We removed one set of branches that were overhanging, limiting two end panels' production.

The turnkey price of installation comes with a 30% federal rebate that is processed with that year's federal taxes (or prorated).  In shameless Michigan, no other incentives are offered, not even tax-exempt parts and installation.  A haircut has no taxes, but renewable energy does.

Stay tuned for a cost efficiency update in a few months, power production and any hiccups along the way.

[Follow Ben van der Pluijm on Twitter: @vdpluijm]

Friday, September 22, 2017

Water World: Sea Level Rise, Coastal Floods and Storm Surges

The coastal land margin of the United States has seen numerous extreme events of historical proportions in just the first two decades of the 21st century. An incomplete list includes Hurricanes Charley and Ivan in 2004, Katrina, Rita, and Wilma in 2005, Ike (2008), Irene (2011) and Sandy (2012), the Louisiana Flood of August 2016, and now Harvey and Irma in 2017.

Common to all is the juxtaposition of resulting floods with displaced people and damaged infrastructure. These seminal disasters will exceed $500 billion in damages, and cumulative loss of lives and suffering are devastating. However, it is possible that these tragedies can serve as Sirens for planning our future.

The salt marshes of Grand Bay National Estuarine Research Reserve in Mississippi are very vulnerable to sea level rise. Using an integrated “system of systems” approach represents a paradigm shift in modeling and understanding the dynamics of the coastal land margin. 
Credit: Matthew V. Bilskie, Louisiana State University

To understand the past, present and future state of the coastal land margin we suggest that a “system of systems” approach is useful. For example, each weather event is a system unto itself that interacts with the built and natural environment. How these systems respond to an extreme condition is better understood by studying the multi-faceted, complex interactions of humans and nature. Add modern climate change and associated outcomes of, for example, sea level rise, and the value of holistic system of systems methodology becomes apparent.

The region where the land meets the sea is a dynamic system. Population grows; shorelines, dunes and barrier islands morph; land use and land cover changes; marshes expand and contract; and with sea level rise these alterations will be magnified.

The coastal land margin is not like the hard edge of a bathtub. When sea level rises in a coastal ocean basin the response in the nearshore regions is best modeled dynamically. The process diagram below illustrates the integrated system of systems approach for understanding the coastal dynamics of sea level rise [Kidwell, et al., 2017].

This represents a recent paradigm shift in computational capabilities and our approaches. A special issue of Earth’s Future, entitled Integrated field analysis and modeling of the coastal dynamics of sea level rise in the northern Gulf of Mexico, provides a comprehensive overview of this shift.  These studies, for example, show that storm surge response to sea level rise is not simply additive. Storm surge flooding for the Mississippi, Alabama, Florida panhandle regions more than double with an overall increase of nearly 140% from present-day (283 km^2 of flooding) to a 2-m sea level rise (672 km^2 of flooding). To put this into perspective, the average land area of a coastal city in Mississippi, Alabama, and the Florida panhandle is 50 to 100 square kilometers. In the same sea level rise scenario, agricultural lands in the region will see an increase in inundation area by nearly 190%, and total inundated land area will increase by nearly 90%.

The nonlinear response to sea level rise is not limited to the northern Gulf of Mexico or other low-gradient landscapes, but applies to coastal regions around the world, creating some of the greatest societal challenges, as exhibited this hurricane season.

Scott Hagen and Ben van der Pluijm (Eos, 2017)

Tuesday, May 30, 2017

Sgt Pepper is 50.

It was 50 years ago today ... 

A new stereo remix of the Sgt. Pepper's Lonely Hearts Club Band album has been released to celebrate its 50-year anniversary (  Remixed by Son Martin it still feels overproduced on several songs, though overall crisper and more balanced than before.  Listen to the mono version, however, and you’d get the Beatles’ preferred sound mix. 

Whereas often considered the culmination of their creativity, the album is uneven.  Its heralded “concept” structure is really Sgt. Pepper's Intro and Reprise bookending several brilliant songs and some lesser fillers, which are mostly unconnected as a set.  Imagine if George Martin had decided to include (Lennon's) Strawberry Fields Forever and (McCartney's) Penny Lane and removed (Lennon’s) For the Benefit of Mr Kite and shortened (Harrison’s) Within You Without You.  Fixing a Hole is also a (McCartney) throwaway.  They might have considered the addition of (Lennon’s) All you Need is Love, which was finalized around that time (or, who knows, Carnival of Light).  The lineup (below, with a few minutes extra) would have eclipsed Revolver, which otherwise remains their creative masterpiece and last true group effort.

Side one

  1. Sgt. Pepper's Lonely Hearts Club Band              
  2. With a Little Help from My Friends      
  3. Lucy in the Sky with Diamonds
  4. Getting Better
  5. Fixing a Hole
  6. She's Leaving Home
  7. Strawberry Fields Forever

Side two

  1. Penny Lane
  2. Within You Without You (shorter version)
  3. When I'm Sixty Four
  4. Lovely Rita
  5. Good Morning Good Morning              
  6. Sgt. Pepper's Lonely Hearts Club Band
  7. A Day in the Life

Friday, May 26, 2017

Ken & Ben on Climate & Engineering - A Reddit AMA

On March 23, 2017, Ken Caldeira, professor and climate scientist at Stanford University, and Ben van der Pluijm, Editor-in-Chief of AGU’s journal Earth’s Future, and professor and geologist at University of Michigan, hosted a Reddit Ask-Me-Anything on Climate Change and Climate Engineering.  

Ken Caldeira works on a broad array of issues including the physical climate system, global energy systems, ocean acidification, and geoengineering. Solar geoengineering involves trying to cool the Earth by deflecting some incoming sunlight away from our planet. Studies have shown that actions like putting small particles in the stratosphere could reflect some sunlight away from the Earth, potentially taking our climate back to a point similar to pre-industrial revolution. Of course, we know for sure about only one habitable planet, and toying around with this planet at the required scale would pose great risks -- but allowing the Earth to warm from our greenhouse gas emissions also poses grave risks.

Ben van der Pluijm works on societal resilience and the impacts of global change. Building on our human history of engineering applications to overcoming societal challenges, climate engineering should be included as a viable solution for reducing the impacts of global warming. Climate engineering takes two approaches: (1) Carbon dioxide removal, and (2) solar radiation management. The former addresses the cause of climate warming by removing a greenhouse gas from the atmosphere ("treat the illness"). The latter offsets the warming effects of greenhouse gases by allowing Earth to absorb less solar radiation ("treat the symptoms"). Given worldwide impact, planning for climate engineering must occur on a global scale, involving all nations, large and small, rich and poor, and not be limited to a few technologically advanced, wealthy countries.

The goal of the Reddit AMA was to advance the conversation about possible solutions to global warming by answering questions about climate change and whether geoengineering techniques can minimize the impacts for ecosystems and people.  Below are selected questions (in bold) and responses from over 200 questions that were posted in a 2-hour window.  Answers are minimally edited for clarity and brevity; questions are verbatim.  The full exchange is posted at and

What's the single most effective evidence of climate change when convincing skeptics?

Ken: I think the instrumental record of surface temperature is the most compelling evidence of temperature change. The fact that the stratosphere is cooling while the lower atmosphere warms is the most compelling piece of evidence that greenhouse gases are behind this warming. Almost everything else (solar variability, changes in ocean heat fluxes, etc) would cause both the stratosphere and near-surface temperatures to move together. The fact that stratospheric temperatures are moving in the opposite direction to surface temperatures is a real smoking gun pointing to our greenhouse gas emissions as the culprit.
Ben: Responses will vary, but I always highlight sealevel rise as evidence (more ice cap melting from warming) and as impact (coast-oriented human society).

Correct me if I'm wrong but climate change is not an issue at the national level, but more at the global level. With such ignorance and denial by leaders of some of those nations, United States particularly, it seems like changing ones worldview is a bigger problem than coming up with or implementing ideas to slow climate change. Nations like the United States were built on coal is it conscionable to tell another nation or enforce carbon tax on emerging nations doing the same?

Ken: Climate change is an issue at every level. The problem is that costs are borne by the individual in the here-and-now but benefits are to the whole world for thousands of years into the future. It is this game theoretic challenge that makes this such a difficult problem.
Ben: Climate change is a shared issue. As a large and wealthy nation, the US should take a lead in addressing the impacts and solutions to change, regardless of our past role. Past behaviors provide valuable lessons for the future. We are in this together.

I understandably get a sense of dread when I read headlines like, "CO2 LEVELS HAVE PASSED THE POINT OF NO RETURN". What does that mean quantitatively, and does it really mean that climate change as a result of carbon emissions is now out of our hands? Are there still steps that can be taken as a species to slow/stop/reverse it? How about on national level? How about on an individual level?

Ken: I am not a fan of these 'point of no return' declarations. Our CO2 emissions may cause damage and suffering, but humans will not go extinct as a result of our emissions. We will always deal with whatever conditions we have. The question is not one of how do we survive, but rather how do we want to live?
Ben: First, having CO2 in the atmosphere is good for us, making for habitable surface conditions. Modern CO2 increases will take decades to show their full impact. Adding more CO2 (and methane) will increase these impacts. We should try to minimize future increases as they have significant impact for human society, but perhaps also consider reducing CO2. The good news: we'll ultimately deal with change one way or another.

Carbon dioxide removal and solar radiation management are both likely to be useful and necessary tools for dealing with climate change - but how are we planning to pay for them? Do you envisage some sort of carbon tax in various countries to raise funds? Governments just deciding to do it on their own? Private donors? What is your most likely source of funding?

Ken: Carbon dioxide removal is thought to be expensive and paying for it will be at least as challenging as paying for CO2 emissions reduction. On the other hand, putting sulfate aerosols in the stratosphere is relatively cheap and would be in the noise of budgets of big countries. The main issue with solar geoengineering is adverse impacts and risk, not direct financial cost of deployment.
Ben: For starters, our changing climate is expensive already. I am not an economist, but do believe that full-cost accounting is the first step in understanding true environmental cost. Then, any remediation efforts may not look too bad. In today's economic world structure, a carbon tax certainly will have an impact. If governments don't step up, hopefully foundations are willing to support action. Also, industry can (and should) play a role.

What are some struggles with renewable power integration? Say we wanted to go 100% renewable by 2050, what would be the biggest obstacle during the transition?

Ken: One of the biggest challenges is dealing with the intermittency of wind and solar electricity generation. Another big challenge is how to decarbonize things like aviation, which today depends on dense liquid fuels. Ultimately, it is largely a question of willingness to pay more for something that works a little less well, but is better for the environment.
Ben: Our current infrastructure is based on fossil fuel energy. In the US, 80+% of energy is still produced this way. Once the obstacle for an energy transition was technology, but today the obstacle is mostly infrastructure (transportation, grid, etc) and embedded interests (industry, job sectors, etc). Price is no longer a large issue.

Solar radiation management (particularly through the injection of sulphate aerosols in the stratosphere) is a form of geoengineering that has seen significant interest among researchers as a potential way to buy time of society can't get its act together to reduce emissions quickly enough. As researchers who have worked extensively on the subject, what do you see as the relative pros and cons of this geoengineering approach?

Ken: The pros are that solar geoengineering with stratospheric aerosols is pretty cheap and easy, and we know from volcanic eruptions that it will basically will work and not cause the world to end. The main cons are that there are likely to be both environmental and sociopolitical downsides that are hard to predict. Risk aversion suggests we would do better to try to reduce our interference in complex Earth-system processes, and that increasing our interference is likely to lead to unforeseen problems.
Ben: Solar Radiation Management, as you describe, would allow us to turn action on and off at will. That is good. However, we must also be sure that neighbors agree with such action. This requires dialogue and shared decision-making.

I recently read a paper that found fracking was producing more leaks than we had previously thought. Is methane in the atmosphere a problem that should be talked about more? Also what damage are we doing to the Earth by using fracking and what consequences might we see? Thank you very much for your time and I wish you the best of luck in your mission.

Ken: There are several issues with fracking. To me, the central question is whether we want to be expanding fossil fuel industries that depend on dumping waste CO2 into the sky at a time when we know that we need to be phasing out such industries. Methane releases associated with fracking are substantial, but with good management policies these emissions can be curtailed. It is much harder to prevent the CO2 from combustion of that methane from reaching the atmosphere. Of course, when fracking is poorly implemented, there is the potential for substantial local environmental hazard.
Ben: Fracking targets the release of the greenhouse gas methane that is buried in geologic (typically shale) formations. The goal is to catch this released gas, but, yes, some escapes. Such leaks are tracked by EPA and NASA agencies, for example. Other issues with fracking are subsurface pollution (like groundwater) and continued fossil fuel reliance. Methane is converted to CO2 for energy production, a greenhouse gas, which contributes to atmospheric warming. As a geologist I also mention the role of human-induced earthquakes from fracking, but that is for another AMA.

How do you feel about Naomi Klein's book 'This Changes Everything' and its conclusion that capitalism is at the Crux of the climate issue and can only be solved by reevaluating that part of our society?

Ken: If we wait to save the climate problem until capitalism is overthrown, we will be waiting too long. The climate problem is not that hard to solve technically. We just need to decide that we are willing to pay for it. Economists estimate that solving the climate problem might cost 2% of GDP. Compare this with the 17% of GDP the US now spends on health care or approximately half of that it spends on the military. We could be more efficient on delivering health care or spend less on the military and easily have enough resources to solve the climate problem.
Ben: I have not read the book, but heard the arguments. One could also argue that capitalism will support change if you and I decide to make our choices accordingly. Oil companies find and sell oil only because we buy it.

What tipping point do you think will end the corporate-sponsored mass denier movements in the west? Or are the courts likely to do it first?

Ken: I push back on the "tipping points" framing. Most changes in the climate system will, I think, be fairly progressive and continuous. Tipping points can happen in social systems, where there is a phase change in human attitudes towards something. It is, of course, challenging to try to create that social tipping point. I guess that I am doing a little but to try to create that tipping point by doing this Reddit AMA.
Ben: The problem with the notion of "tipping points" is that climate change is gradual on the human scale. Perhaps looking back we will see the aggregate of impacts as a tipping point, but day-to-day we see mostly annoyances. Their costs might be the ultimate driver for changing our practices. My fellow geologists in a future, far, far away will likely see a tipping point in our reaction.

Curbing CO2, methane, etc is politically and practically very, very hard. Will geoengineering be our only option? How smart are we to pull this off?

Ken: Phase changes in social systems are possible. People used to accept slavery and no longer accept slavery. Few people foresaw the fall of the Soviet Union. Few people thought Congressional Republicans would be supporting protectionist trade policies and support a pro-Russian President. So, the unexpected can and does happen. I am still hoping for and working towards a change in social attitudes towards using the sky as a waste dump for our CO2 pollution. I am hoping this will result in a major transformation of how we obtain and use energy. But, I don't want to put all of my eggs in one basket, so I also want to understand whether and how geoengineering options might be able to reduce suffering and damage in both human and natural systems.
Ben: If we stop producing atmospheric CO2 and methane today we will still see climate change for decades to centuries, because the atmosphere is slow to react. So, first, we have to live with change, and, second, we want to minimize further change. The latter can occur by greenhouse gas emission reduction policies, and by geoengineering, the topic of this Reddit-AMA. Either way, we are smart enough to deal with change.

Thursday, February 09, 2017

vanderTrick: Download a Facebook video

Facebook videos do not offer a simple "Save video as ..." option, but it is actually quite easy to do so without installing software.
Follow these steps (on a PC):

  1. Change the "www." in the URL with "mbasic." from to, which opens Facebook's mobile site.
  2. Click on video to start play and, while playing, right click the video and select "Save video as ...". Select a location to store the video.
  3. Rename video file to something more understandable than 16704569_248739545738440_761492445729461088.mp4
  4. Make sure to give appropriate credit to the original poster/owner and/or include post link (e.g.,

Done !

Thursday, January 26, 2017

Good Night Sunshine -- Geo-engineering Solutions to Climate Warming?

The goal of last year’s Paris accord to limit global warming to 2°C (=3.6°F), if not 1.5°C (=2.7°F), is admirable, but it’s unlikely that these aspirational goals can be reached with voluntary greenhouse gas emission reductions alone.  Already, we are nearing the 1.5°C global warming level, with predictions for reaching 2°C not far into the future.  The implications of global warming are recognized widely, both in short-term events like coastal inundation and extreme weather, and long-term in the form of permanently shifting climate zones and higher sea level.  The range of our actions, however, is not limited to greenhouse gas generation only.

Building on humanity's remarkable history of engineering approaches to overcome challenges--from early use of fire to create stronger tools, to modern manufacturing and construction-- climate engineering techniques should be included as viable solutions for reducing the impacts of global warming.  Investigations of geo-engineering approaches have been around for several decades, but have grown especially since the 2006 publication of Dutch Nobel Laureate Paul Crutzen’s editorial essay on reducing solar influence, called “Albedo enhancement by stratospheric sulfur injections: A contribution to resolve a policy dilemma?”

Climate engineering takes two approaches: (1) Carbon dioxide removal (CDR), and (2) solar radiation management (SRM).  CDR addresses the cause of climate warming by removing greenhouse gas from the atmosphere ("treat the illness").  SRM offsets the warming effects of greenhouse gases by allowing Earth to absorb less solar radiation ("treat the symptoms").  Reduction of greenhouse gas emissions, as proposed in the Paris Accord, is desirable, but is not a prerequisite for climate engineering.  Among the range of techniques, SRM, the focus of Crutzen’s essay, is the main source of professional and public anxiety and has mostly remained taboo.  There are concerns about unintended consequences, local applications with global consequences, runaway effects, and even climate warfare.

Given that climate engineering remains highly controversial, a set of thoughtful research papers and scientific commentaries have been published on this in AGU’s open-access journal Earth's Future, introduced by Boettcher and Schäfer (2017).  This thematic collection examines the techniques and risks of climate engineering, from specific methodologies to socio-political dimensions.  The contributions highlight our much improved understanding of the environmental, political and societal risks and benefits of climate engineering, but they also recognize that the current state of our knowledge is insufficient for reliable deployment.  Computer modeling and integrated assessments have advanced the positive and negative aspects of various techniques, allowing for an informed public debate and eventual decision-making.  Some nations more than others are advancing this understanding and are considering some implementation.  However, more extensive scientific efforts and social study that includes real-world, outdoor experimentation will be needed to adequately assess near-term deployments and their impact.

Climate engineering has unquestionable potential to limit global warming when coupled with currently available technologies, but the scientific, social and ethical dimensions of implementation are not sufficiently examined.  Given the worldwide impact of most deployment approaches, planning should occur on a global scale, involving all nations, both rich and poor, and not be limited to a few technologically advanced, wealthy stakeholders.  We know we must limit the impacts of global warming, but we also know that warming will continue for decades or centuries even with radical reductions in greenhouse gas emissions. This situation generates an urgent need to invest in research and impact analysis of climate engineering approaches.  Judging by the resilience of today’s human society to global environmental change, ignoring the potential of climate engineering solutions does not seem prudent nor realistic.

Ben van der Pluijm, University of Michigan-Ann Arbor, USA.
Guy Brasseur, Max Planck Institute for Meteorology, Hamburg, Germany.

Crutzen +10: Reflecting upon 10 years of geoengineering research.  Earth's Future Special Collection (2016/17).
Photo credit: Abode Stock #113493276. Art credit: Kiel Earth Institute
Modified from American Geophysical Union's Editors’ Vox.