Category: Environment

Posted on

Home cooling 2

As a consequence of global warming architecture has to cater for the cooling of our homes as well. The 1st option is to keep the heat outside. Isolation is key in this respect as well. Colors outside have a long tradition in protecting against heating up due to abundant sunshine. Doors and windows ask for additional protection as well. Historically, trees have been instrumental in providing shade for homes. Greening of facades is another natural option. For a long time homeshomes have been built above an underground floor or a cellar. Originally these naturally cool rooms served as storage rooms for food and drinks. Nowadays, such basements offer additional cool space during (exceptionally) hot summer days. The distribution of cool air from basements to upper floors is an alternative way of cooling, which uses little energy. For newly built homes this is another reason to drill builders drill. Even office space has been built in this way, much appreciated during the warm seasons. (Image: Paris UNESCO headquarters office space). 

Posted on

Home Energy

Energy production and consumption in a home are determined by many factors. The number of persons in a household has, of course, a considerable impact on consumption patterns. The investment in home energy production can cover the basics, but is less likely to cover peaks of consumption like friends on a visit wanting to charge their electric vehicle.
In a test with a simple small scale solar panel (fixed on a balcony for example with 860W peak) it was possible to produce a full days consumption on a sunny summer day for a 1-2 person household without use of electricity for personal mobility, but hot water through heat pump provision. The potential for an own production of electricity during summer months is within reach without major behavioral changes.
Okay, digital steering of energy consumption for hot water during hours of bright sunshine and washing machine around high noon are not for everybody to program or carry through.
Digital tools complement the energy consumption at the right time. There is a lot of power in sunshine. The usual caveats of bad weather and winter months change the calculations. The return on investment or break even point needs 300 days of about 2 kWh to recover the 500€ initial costs of the solar panels. After about 3 years the initial costs are recovered and savings begin to accrue. The bridge between energy theory and practical applications is to be found in experimental setups and tests of different scenarios for the modern “prosumer” of the 21st century.

Posted on

Energetic Architecture

The link between energy and architecture is all to obvious. For at least a century we believed that energy had to serve architecture and could be relegated to second place. With global warming the overriding importance sits with energy concerns for some years to come. We spend billions to repair the bad architectural and fast growth architecture of the post 2WW era of architecture, especially the construction boom of the 60s and 70s. The driver of change in architecture has moved from the period of social architecture (60s, 70s) to energetic architecture. Energy in architecture has multiple dimensions. Whereas a century ago the shift consisted in the installation of central heating systems in the northern hemisphere of the globe at scale, in the 21st century the concern there shifts to isolation from heat (and cold) to more efficient, less polluting energy provision. Cooling houses and office spaces during extended periods and higher peeks of heat, ask for substantial revisions of existent architecture and the next generation of energetic architecture. Before long, we shall also think more seriously about the handling of water in architecture, a topic which is closely linked to energy consumption and design.
From a sociological point of view we are used to ask questions of social inequality related to this issue as well. We are on the way to move into a society of energy-rich versus energy poor households and enterprises. Financing of adaptations of housing and offices to the energetic challenges is likely to create severe additional inequalities, which exacerbate the already existing ones. If you have no money to spare, you will be unable to invest into energy savings with more distant returns on investment (ROI). At older age you are less resistant to heat waves and causes health disadvantages. If previous investments were impossible or the urgency for energetic architecture was neglected for too long, additional health inequalities shall arise.
The “Deutsches Architekturmuseum” has built an exhibition around this theme, which widens the perspective of architecture and energy. This highlights the additional concern for energetic architecture and people living or working in (modern) architecture.
(Image Trier Roman arena 2025)

Posted on

Global warming

The annual update of the global warming indicators (source: Earth system science data 2025-6) gives more reasons to worry about the future of our climate. The objective to limit global warming to +1.5°C, established at the Paris climate agreement in 2015, is no longer achievable. This is the hard evidence based on the global network of scientific data collections and their projections. Fossil fuels are a major cause, deforestation and greenhouse gas emissions as well (Forster et al. 2025). As a consequence, human-induced warming of average surface temperatures and flows of heat into oceans continue. The first consequences, we witness in many parts of the world already. France is particularly affected (Le Monde 2025-6-20, p.7). What used to be called “natural disasters” is better described as long-term consequences of human-induced global changes like global warming. About time to take our CO2 footprint even more seriously. The “All electric society” can reduce reliance on fossil fuels considerably, as of now.

Posted on

Fertility Fecundity

The scientific debate around changes in fertility has focused on social, economic and cultural factors to explain the drop in total fertility rates in OECD countries. The baby boom years of the 1950s and early 1960s had come to an end following the spread of new forms of birth control like contraception from the late 1960s onwards. The trend is very obvious and yet, the explanations of the trend might lack a more profound analysis of fecundity in addition to the socio-economic explanations. Shakkebaek et al. (2025) point for example to the little known effects of environmental (pollution) factors on the biological reproduction capability of humans (men and women).
Additionally, psycho-social factors like “the German Angst” fear about future developments in many social and economic fields might have direct effects, but also indirect effects on human biology. We know still very little about such feedback loops or feedback effects. We are more convinced, than we actually have hard evidence, that the BSP, SPB or PSB (B=Bio, S=Social, P=Psycho) spheres are interwoven, but an ambitious research agenda is called for to enlighten the issue. The big invisible elephant in the room might be environmental issues that enter into the fertility equations more than we have expected for many years. A nice working hypothesis for an ambitious and overdue research agenda.

Posted on

Home cooling

In the summer months, in Europe, the concern shifts from heating your home to cooling your home. For generations this has been possible without use of air conditioning. A natural way of cooling has been for centuries to dig into earth to take advantage of the rather stable and cool temperatures underground. In home building this has also been a tradition for centuries to build cellars underneath a home.
Wine growing regions have used the cellar as a natural cooling facility for long and short term storage of wine. Digging into a mountain of a valley offered a natural cool storage solution for years without additional energy consumption. Modern buildings should return to this practice and gain cold from below the surface to cool buildings in the warm or hot seasons. Good isolation combined with the cool temperatures from below the surface in summer months will substantially save energy and thereby CO2 emissions. Circulation of the cool air from below to the upper floors is the issue as well as dealing with differential humidity levels. The wisdom of previous generations in home building with no access to air conditioning (avoiding the air conditioning paradox) is likely to experience a revival in the coming years.
Coolness is the new and old wisdom.

Posted on

Warming continues

The global warming continues to change our landscapes. Heat waves, droughts and flooding become more often. Average temperatures keep rising. The evidence from meteorological data is showing this beyond doubt. Our forest take the toll and reports document the worsening situation for many trees (Germany and Switzerland). An adaptation will take years if not decades. In the region around Paris some home owners have started or been forced to adapt their gardens to the warming weather conditions. Trees that do not support the consequences of warming die and we witness the changing of the landscape. Palm trees near Paris have survive for years by now near Paris and can grow rather tall.
Like it or not, the visual landscape will change despite the many great initiatives launched by the city of Paris to stop the warming of the city.

Posted on

Rainwater Use

The use of rainwater is fairly easy to realize. Most homes in Europe and beyond have a roof drainage system in place. However, for decades the only concern was to get rid of the water as soon as possible. Nowadays, we think twice about it. The recovery and storage of rainwater for a separate use in a household has become a substantial cost saving exercise. In the Paris region in France you can expect on average 650 liters of rainwater per year per square meter. For a roof size of, for example, 70 m2 this yields about 45.000 liters per year. If you take a shower using 40 liters this allows you and your household to take 1125 showers or 3 persons almost one shower every day. Average household consumption in Paris is 120L/day, which adds up to about 44.000 liters per year for washing and toilet use. On a monthly basis with a storage capacity of 4000 liters of rainwater per adult person you should be able to manage your own consumption with your own roof drainage system. It is a rather simple use case. Maybe during dry summer months the calculation is a bit too optimistic, but the potential for a water autonomy of households in Europe is an option. In addition to the dry January, the no mow May, we shall have the no shower July next. 

Posted on

Smart Heat Pumps

The potential to reduce CO2 emissions through the replacement of fossil fuels with heat pumps is huge. The technology is well known and has reached a considerable amount of maturity in the mid 2020s. Noise is much less an issue even at higher compression rates and during the use of booster functions to cater for peaks of hot water or home heating. Combined with solar energy the local production and consumption of energy turn each household into a “prosumer” of energy. Besides the initial investment you have to find capable technicians and enterprises that master the installation of the technology with the necessary care and ensure the adequate calculation of the envisaged energy needs of the household. Household and family size matter, and this is not easy to project into the future. Additional saving potentials can be harvested through the use of smart home applications. Switch off the heating before you leave or if a longer than previewed absence occurs. Just do it if you are away from home. Alternatively, just start the heating when you get on your way back home from work rather than at previously estimated, but fixed times. Smart technology is just perfect for such use cases.

Posted on

Citizen Walk

Capitals like Paris and Berlin make great efforts to improve the walkability of their cities. After decades of focus on automotive traffic and mobility and the detrimental effects on health for several generations of people, the awareness that walking citizens are part of the solution is spreading. Citizens of Paris voted in a referendum to stop circulation of cars in 500 more streets. In Berlin pedestrians unite to mobilize more people to take to the streets as well and reclaim walking space. In high density spaces like metropolitan areas it is possible to reach all major amenities within a reasonable walking distance. The more spread out suburban area, however, leve fewer options to walk and carry your shopping or do your dily commute to work while walking. Fewer cars and pharmaceutical products sold would mean less „artificial economic growth, but more healthy and happy citizens. It will take decades again to realize such visions.