Climate Change

Climate change is affecting different aspects of our lifes

​The basics


Let’s first understand what ‘climate’ means. People often confuse climate with weather, but they are two very different things. Weather describes the condition of atmosphere over a short period of time. Humidity, air temperature and pressure, wind speed and direction, cloud cover and type are all atmospheric characteristics of the momentary conditions we call ‘weather’. On the other hand, we can describe climate as the average weather of a long period of time of an area or a country.

​Earth’s Climate


Earth’s climate has and will always vary for natural reasons. Throughout the history of the Earth there have been both long and short-term periods of climate change.

During the periods of Ice Age, the temperature of Earth changed, being around 4°C. The last Ice Age ended about 11.000 years ago.

There have also been short periods of climate change at a regional level.. For example, in Europe from 10th century until the 13th century, the Medieval Warm Period was characterised by slightly warmer temperatures, followed by a period of colder weather, the Little Ice Age.

​What’s happening now?


Over the last century our climate has started to change rapidly again. According to scientists, this is due to increased amounts of greenhouse gases in the atmosphere.

Solar energy warms the Earth’s surface and, as the temperature increases, one third of this energy is reflected back into the universe. The remaining two thirds of solar energy is absorbed within the atmosphere, the oceans and the warming land.

In this situation, the atmosphere acts like a greenhouse, letting in the visible lights and absorbing the outgoing infra-red energy. This natural process is called the “Greenhouse Effect”, which is very important considering that without it Earth’s average temperature would be -18°C.

So what is the Problem?


The problem is that human activities have enhanced this natural process, the greenhouse effect, by adding greenhouse gases, such as carbon dioxide, methane and nitrous oxide, to the atmosphere. The results of these human activities include the rise of atmospheric temperatures, rising sea levels, melting glaciers, changes in rainfall patterns and many more effects.



Monuments are the living testimony of our past. Their safeguarding may be spontaneous but it is also often prescribed by state laws and international declarations. It is obvious that to safeguard and protect, one must know the threats and associated risks. The threats, an indicative list of which you can read in the following panel, can be affected both by natural and/or anthropogenic factors, and often by the combination of more than one factor. The threats can affect monuments locally, regionally or globally. It is obvious that climate change plays a direct role in some of these threats, consequently affecting the preservation of the monuments of the geographical area affected by the change of the climate.

Indirect effects


Indirect effects of climate change in creating alteration, or decay and deterioration, relating to and mediated by human activities are produced by:

  1. Migration (permanent/ temporary)
  2. Conflicts
  3. Changes in value systems/ politics
  4. Changes in production/ consumption related to:
    • Agriculture
    • Industry
    • Urbanization/ settlements
    • Deforestation
  5. Changes in polluting elements

Resources: notes from the round table on Climate Change and its Impact on Preservation Management of Archaeological sites, Athens, April 2012

Direct effects


Direct effects of climate change in creating alteration, or decay and deterioration, which may be at a local or regional level, are produced by:

  1. Variation in soil/ moisture and/or desertification
  2. Flooding and surface runoff
  3. Extreme weather events ( floods, surges, hurricanes, storms)
  4. Coastal erosion
  5. Freeze and thaw- glacier variation
  6. Formation of salts
  7. Quality & typology of the biological environment of the area and its flora/fauna
  8. Variation in temperature
  9. CO2 emissions
  10. Corrosion and earth recession

Resources: notes from the round table on Climate Change and its Impact on Preservation Management of Archaeological sites, Athens, April 2012



As DECAY of a monument we would define any chemical or physical modification of its component materials that lead to a loss of value or to the impairment of its use. When a monument undergoes changes in character and deterioration due to chemical or mechanical process by exposure to weather, we tend to call it WEATHERING.

Although monuments suffered from several deterioration factors in the past, the climate change came to enhance this process and put monuments at greater risk. It is observed that climatatic changes during the last decades have caused more problems to the monuments than all the previous centuries or even millennia of their existence.

Whether climate changes are responsible directly or indirectly for the deterioration of mankind’s tangible creations, their effects are evident and a series of monuments can provide us with characteristic examples to prove it.

Resources: ICOMOS

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