Page 215 - Materials Chemistry, Second Edition

10 Life Cycle Impact Assessment 201

provide a complete and updated qualitative comparison of widely used LCIA
methods available in current LCA software.

10.6 Climate Change

10.6.1 Problem

The greenhouse effect of our atmosphere, discovered and explored from the early
th
19 century, is vital to life on our planet and has always existed since the dawn of
life on Earth. Without it the global average temperature of our atmosphere near the
ground would be −18 °C instead of currently 15 °C. Hence, there are natural
drivers and sources keeping it in balance (with periodical imbalances leading to
natural events such as ice ages). In addition to those, anthropogenic activities also
contribute to this effect increasing its intensity and creating global warming, which
refers to the phenomenon of rising surface temperature across the planet averaged
over longer periods of time. The Intergovernmental Panel on Climate Change
(2014a) (IPCC) defines climate change as “a change in the state of the climate that
can be identified (e.g. using statistical tests) by changes in the mean and/or the
variability of its properties, and that persists for an extended period, typically
decades or longer”. IPCC observed an acceleration of the rise in planetary surface
temperature in the last five to six decades, with the highest rates at the very northern
latitudes of the Arctic. Ocean temperatures are also on the rise down to a depth of at
least 3000 m and have so far absorbed most of the heat trapped in the atmosphere.
Tropospheric temperatures are following similar trends as the surface. Although,
still debated by few sceptics, most scientists agree on the presence of this effect with
anthropogenic activities as the main cause. These are also the focal point of LCIA
methodology and hence of this chapter.
Effects observed by IPCC with varying degrees of confidence based on statistical
measures (IPCC 2014a):
• Rise of atmospheric temperature with the last three decades from 1983 to 2012
being very likely the warmest 30-year period of the last 800 years in the
Northern Hemisphere and likely the warmest 30-year period of the last
1400 years
• Rise of ocean temperature in the upper 75 m by a global average of 0.11 °C per
decade from 1971 to 2010
• Melting of glaciers, snow and ice caps, polar sea ice and ice packs and sheets
(6¼polar sea ice) and permafrost soils
• Rise in global mean sea levels by 0.19 m over the period 1901–2010 (due to
thermal expansion and additional water from melting ice)
• Increase in frequency and intensity of weather-based natural disasters, essen-
tially due to increased atmospheric humidity and consequent changes in