Sun Rays and Water at the Heart of Both the Cause and Effects of Climate Change.

by | Aug 26, 2020

Climate change definition is sometimes misunderstood. A clear and undisputable physical explanation of planet Earth’s temperature changes is not clearly specified. Consequently, climate deniers conveniently insist that climate change is not anthropogenic and human-made. Where is the truth? Let us look at the solar energy distribution as it reaches the planet Earth.

Sun radiation, coming from a distance of 150 million square kilometers away to accompany mother Earth, will reach the upper layers of the atmosphere with 1351 – 1431 watts of energy per square meter. Humankind can survive because the solar energy distributes over the planet’s surface.

As sunlight passes through all the layers of the atmosphere, 47% of it is absorbed.  At the ground level, five to ten percent of solar energy is utilized by heating the ground surfaces. Another five to ten percent of solar energy reflects and bounces off to the atmosphere. The remaining 80-90 % of sun radiation converts to either latent or sensible heat, depending on the state of water volume in the region.

The first law of thermodynamics asserts that energy cannot be created or terminated; energy can only shift from one form to another until they are balanced. Per this law of energy conservation, when the ground contains plenty of water, 80% of the solar energy transforms into latent heat.

Evaporated water transports the latent heat to the colder layers of the atmosphere.

When water vapor condenses, we can see clouds. The Earth’s heat balance law guarantees that when the rain forms at the dew point, latent heat turns to sensible heat. The latent heat warms up the colder layers of the atmosphere at this point in the energy transfer.

As air heats up, it becomes less dense and rises, conveying its energy upward.

During water transition from one phase to another, from gas to liquid, latent heat is interchanged during condensation. In other words, condensing water vapor releases latent heat, which drives much of the atmospheric circulation. Latent heat and, therefore, water vapor propel the energy in climate. Radiation, convection, conduction, etc. are part of the energy exchange. This smart thermal regulation of ecosystems had been in place for thousands of years until humans began to alter Earth’s surface.

In the Anthropocene era, people began to “dry out the Earth” by draining the ground surfaces, altering watersheds, depleting aquifers, damaging the vegetation, and destroying forests. The more we drain the landscape and watersheds the less water evaporates. The less water evaporates, the less moisture is prepared in the atmosphere to “extract” latent heat from the warm troposphere into a cooler atmosphere.

Allow us to add for better understanding, that a healthy water-saturated ecosystem can evaporate up to 10 mm of water on a summer day.

When people alter the environment and for instance pave the parking lot with an impermeable surface such as asphalt and equip it it with the rainwater drainage, they guarantee almost zero evaporation.

When people alter the environment, such as paving the parkinglot with an impermeable surface such as asphalt, equipped with the stormwater drainage, they guarantee almost zero evaporation.

The impermeable surfaces produce 70 MWh of sensible heat per day per hectare, amounting to about 2,800 MWh per year. Such an alarming amount of sensible heat remains in the troposphere, the lowest level of the atmosphere, warming it up by several degrees.

Global Warming. The Global Rain Water Runoff Management Crisis is a Water Crisis.

We estimate that there will be an annual new urban development of 57 000 km2 in the average on the surface of the Earth. Currently, most urban storm management systems ensure that the ground is dry as soon as possible, and stormwater runoff is drained to the nearest river, heading to the sea.

Photo Credit: Shane Phillips at the Better Institutions 

Rainwater presents to be a mere urban inconvenience. That means that less water evaporates from the paved area, and less latent heat transfers upwards to the colder atmospheric layers. 

It is necessary to take into account that if an initial area of 57 000 km2 becomes urban and built-up each year, that means that in 20 years, more than 1 million km2 of land gets drained and dried up, depleting its groundwater resources, suppressing the amount of evaporation. 

Let us take a conservative approach and estimate a 100 mm per year decrease in evaporation from these areas. Such a reduction of water vapor volume would correspond to 100 billion m3, resulting in corresponding changes in the tropospheric sensible heat flux. More than 70 000 TWh of sensible heat result ensues.

Urbanization, coupled with deforestation (about 127 000 km2 per year) and the improper agricultural landscape drainage practices (about 200 000 km2 per year), complete the picture. Civic and agriculture development, and timber harvesting, pull the plug on watersheds. (Pun intended).

In that case, over time, we will experience dizzying changes in the Eart’s energy flows that shape the thermal regulation. The interaction between the Earth’s energy flows regulate the Earth’s temperature to make sure the Earth’s energy budget is balanced.  

Unfortunately, the thermal energy exchange is not part of the current climate models. We need to broaden our discussion.

Why? Why are we focusing entirely on trends in atmospheric CO2?

Changes in greenhouse gases determine the climate properties. Did we forget that water vapor is the most potent greenhouse gas?

Why don’t we pay more attention to the impact of water phases on the Earth’s thermal regime variations?

Water should be the heart of both the cause and effect of Climate Change. As our team pointed out in the New Water Paradigm, we can mitigate Climate change with understanding the water vapor properties. Restoration of small hydrological cycles will renew the balance.


Author: ©2020 Michal Kravčík

Translated by: Zuzana Mulkerin

More information:  People and Water,  New Water Paradigm, Rain for Climate.

Photo credit: Bob Ward on Pexels, Life Of Pix,  Quang Nguyen Vinh, Michal Kravčík.