Influencing the weather
The conscious influencing of the weather serves to generate locally desired weather conditions or to ward off harmful weather or climatic influences on people or on valuable facilities. For influences that manifest themselves more or less unintentionally as a product of human activity, see under climate change .
Methods for influencing small-scale weather
With in-depth knowledge of the laws of nature, it is now possible to influence certain meteorological processes on a small scale, above all to mitigate extreme weather conditions:
- In fruit - and wine regions can be damage frosts prevented by strong smoke generated that the broadcasting of the ground and the lower layers of the atmosphere reduce or antifreeze irrigation , in which the released heat of crystallization protects the flowers.
- Also of water (lakes, ponds and ditches) cause a certain frost protection for the surrounding surfaces. The effect is particularly noticeable in fruit-growing areas such as the Altes Land during flowering.
- In steppe areas , so-called protective forest strips can be established by planting suitable tree species , which reduce drying out by the wind and thus evaporation . This improves the soil water balance, promotes dew formation and reduces the risk of snow drifts .
- Damage from lightning strikes can be reduced by installing lightning rods or attaching lightning rod systems to buildings. The high voltages between the thundercloud and the ground are preferably discharged via the highly conductive lightning rod.
The so-called "cloud vaccination" method is controversial in terms of its actual effectiveness. By introducing artificial crystallization nuclei (" carbon dioxide snow ", silver or lead iodide ) into existing clouds, the amount of precipitation in dry regions is to be increased, and storm events are to be controlled and avoided, e.g. B. in the area of hail defense .
Methods for influencing weather and climate over a wide area
Large-scale weather and climatic conditions
The large-scale influencing of the weather or even the climate is still in the experimental stage. Various research groups have developed the first theoretical and practical approaches to manipulations, which are tried again and again.
There were even discussions about sealing off the Bering Strait in the Arctic Ocean and at the same time pumping warm water from the Pacific into the Arctic Basin to make the Arctic's climate milder. In doing so, however, the ice masses would melt and the sea level would rise, which would be an undesirable effect.
In the vicinity of airports and at intersections of flight routes, cirrus clouds from contrails can form more effectively in terms of weather . The deliberate enhancement of this effect with chemical agents was proposed in a US patent as a method against global warming . However, recent research, which is very controversial, predicts increased warming due to more contrail cirrus clouds.
Larger scale trials are being undertaken in the People's Republic of China . It maintains a state "weather change office", which ensured good weather at the Olympic Games in Beijing in 2008 or at the celebrations for the 60th anniversary of the founding of the People's Republic on October 1, 2009. To this end, airplanes spray chemicals that rain clouds away from the capital. As a countermeasure against a persistent drought, rain was supposed to be produced in November 2009, but the manipulations triggered an unwanted snowstorm that caused difficulties in the capital. Such measures to generate precipitation are also being considered in Venezuela and Russia , while in Bolivia an attempt was made to inoculate the clouds during a drought period in early 2017.
Example hurricane
A research group led by Ross N. Hoffmann from the US company Atmospheric and Environmental Research (AER) in Lexington (Massachusetts) used the example of the hurricane to investigate the extent to which a major storm can be manipulated and whether this can avoid harmful or destructive effects. To do this, it was first necessary to be able to predict the course of a hurricane with absolute accuracy, which was particularly difficult because the earth's atmosphere, as a chaotic system, is extremely sensitive to the slightest disturbance. Predicting the course of a hurricane turns out to be difficult in the area of the boundary layer , because there can no longer be spoken of a closed system , since heat is exchanged with the sea surface. The computer simulations are therefore approximations based on predictions.
The research group proposed the following theoretical possibilities for changing certain parameters:
- Raising the temperature in the atmosphere, with which the condensation of water vapor and thus the formation of clouds can be prevented, by microwave rays from solar power plants in orbit , which is currently not feasible.
- Reducing evaporation from the sea surface through the application of biodegradable oil films, which would also make cloud formation more difficult.
- targeted adaptation of flight routes to form contrails (see above).
- Use of field irrigation to change the rate of evaporation in a locally limited manner.
The researchers warn of the danger that targeted weather manipulation can be used as a weapon, i.e. to harm others. So the dangers and benefits have to be weighed against each other. ( ENMOD convention )
Worldwide climate
There is broad scientific consensus that the introduction of greenhouse gases such as carbon dioxide and certain hydrocarbons into the atmosphere leads to global warming and associated climate change. The regional effects are uncertain, but everyone agrees that this will also lead to regional changes in the weather. In addition to global warming , northern Europe could also temporarily cool down, for example due to a weakening of the Gulf Stream or cold spells caused by shifting the polar jet stream.
Enactments and prohibitions
Environmental Modification Convention
The ENMOD ( Environmental Modification Convention ), which was agreed under the umbrella of the United Nations in 1977, prohibits the signatory states from deliberately damaging the environment in a conflict or from using such damage to the environment as a military advantage or weapon. In particular, it prohibits any form of influencing the weather for military purposes. The convention was ratified by 77 countries by June 2015, including Germany, Austria, Switzerland and the USA.
United States
In 2005, legislative proposals to authorize experimental weather changes were submitted to the Senate and the House of Representatives , but were not approved.
See also
literature
- Ross N. Hoffman: Hurricanes on a leash . In: Spectrum of Science 08/05, p. 31 ff.
- James Roger Fleming: Fixing the Sky: The Checkered History of Weather and Climate Control. Columbia University Press, New York 2010, ISBN 978-0-231-14412-4 .
Web links
- SWR2 Wissen: Die Wettermacher , broadcast by Udo Zindel on influencing weather, broadcast on July 8, 2008, accessed on July 20, 2011
- Analysis of the efficiency of hail defense in Styria based on case studies uni-graz.at, (PDF file; 4.73 MB, accessed on October 28, 2010)
- Weather as a Force Multiplier: Owning the Weather in 2025 USAF 1996, @ Federation of American Scientists , accessed October 28, 2010
Individual evidence
- ↑ Tagesschau from November 4, 2009: Frosty times for state weathermakers ( Memento from November 7, 2009 in the Internet Archive )
- ↑ Antje Blinda: State weather maker: Artificial snowstorm freezes Beijingers . In: Spiegel Online , November 4, 2009.
- ↑ Venezuela is planning artificial rain. In: Basler Zeitung , November 29, 2009, accessed on January 23, 2010.
- ↑ Elke Windisch: Fighters against snow. In: Tagesspiegel , December 10, 2009, accessed on January 23, 2010.
- ↑ Bolivia usas sus aviones C-130 Hercules para provocar lluvias , Infodifesa.com, February 1, 2017
- ↑ IPCC (ed.): Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change . Geneva 2014 ( ipcc.ch ).
- ↑ See e.g. B. Wei Liu et al. a .: Overlooked possibility of a collapsed Atlantic Meridional Overturning Circulation in warming climate . In: Science Advances . tape 3 , no. 1 , January 4th 2017th
- ^ Daniel Lingenhöhl: The weather is making waves. In: Spektrum.de. November 22, 2013, accessed January 7, 2017 .
- ^ Convention on the prohibition of military or any other hostile use of environmental modification techniques. In: United Nations Treaties Collection: Multilateral Treaties Deposited with the Secretary-General. Retrieved January 25, 2017 (text of the Convention and status of ratification).
- ↑ S. 517 (109th): Weather Modification Research and Development Policy Authorization Act of 2005. In: govtrack.us - congress - bills. Retrieved January 25, 2017 .
- ↑ HR 2995 (109th): Weather Modification Research and Technology Transfer Authorization Act of 2005. In: govtrack.us - congress - bills. Retrieved January 25, 2017 .