In a paper last year, Professor Robert Pindyck from the Massachusetts Institute Technology concluded the so -
called integrated assessment models used to combine climate science with economics have «crucial flaws that make them close to useless as tools for policy analysis».
There are six EMF 22 scenarios and one CCSP scenario with similar population trajectories to the RCP4.5; however, it should be noted that all of these scenarios were produced by
integrated assessment models from the Pacific Northwest National Laboratory.6 However, the range in population estimates in 2100 across the 28 scenarios is small; the largest population estimate is only 20 % higher than the lowest.
Prof Pete Smith, chair in plant and soil science from the University of Aberdeen, pointed out that 80 % of
global integrated assessment models apply NETs extensively to achieve 1.5 C, despite considerable technical, economic, social and political uncertainties.
Incorporation of information typically used as input assumptions
by integrated assessment models of the global energy - economy - land use system, or by global - scale climate impact models of different sectors.
However, for use
with integrated assessment models, energy balance models, and — most importantly — for writing of treaties and legislation — it is still generally necessary to translate all GHG's into some equivalent in terms of CO2.
The process for preparation of scenarios has also changed, and has become a more open, interdisciplinary process with a larger number of interactions across the climate modelling, impacts / adaptation / vulnerability, and
integrated assessment modelling communities.
A short note
on integrated assessment modeling approaches: Rejoinder to the review of «Making or breaking climate targets — The AMPERE study on staged accession scenarios for climate policy»
At the time the 1.5 C limit was adopted, I think the best pathways we had in the literature from
complex integrated assessment models of energy and economy together were about a 50 % probability, at best.
Integrated assessment models create scenarios for the most cost - effective transition toward a sustainable supply of materials and energy while taking the planetary boundaries into consideration.
Here we use a
single integrated assessment model that contains estimates of the quantities, locations and nature of the world's oil, gas and coal reserves and resources, and which is shown to be consistent with a wide variety of modelling approaches with different assumptions, to explore the implications of this emissions limit for fossil fuel production in different regions.
Can science results be used effectively in policy -
oriented integrated assessment models that are our only tool for evaluating global - level impacts of policy and climate change, particularly with regard to land use?
IIASA will
contribute integrated assessment modelling and policy analysis to the project, which will be integrated with an Earth system model run by the University of Versailles, and calibrated using field data on nutrient limitation from researchers at CREAF and the University of Antwerp in Belgium.
Because all four
participating integrated assessment models, and all receiving climate models, use different characterizations and definitions of land use types and transitions, a harmonization step was necessary.
While running the DICE model (and
similar integrated assessment models) may be a useful academic exercise in anticipation of solving these very serious problems, the results at this time are nowhere near reliable enough to justify trillions of dollars of government policies and burdensome regulations.
The model uses information on water demand and availability provided by existing global
integrated assessment models at IIASA, including the Community Water Model (CWATM); the Model for Energy Supply Strategy Alternatives and their General Environmental Impacts (MESSAGE); and the Global Biosphere Management Model (GLOBIOM), and provides information on water resources development, allocation and cost to those models.
I can also see that a result which could be interpreted as «Oh, if we start doing 2ppm a year in carbon - dioxide reduction in 2100 everything except RCP8.5 looks more or less OK, ice - cap-wise» would carry risks, just as using unspecified negative - emissions technologies in
integrated assessment models does.
A proper valuation of carbon will never be done by political ideologues and climate alarmists in the administration, nor by ivory tower university inhabitants that churn out compliant studies and
canted integrated assessment models in return for reliable federal funding.
Together with his Norwegian and US colleagues, junior professor Dr. Stefan Pauliuk at the Faculty of Environment and Natural Resources at the University of Freiburg undertook the hitherto most comprehensive review of five major so -
called integrated assessment models.
The reference scenario accounts the UN's medium fertility population projections, historical GDP per capita rates that converge over time to be consistent with
other integrated assessment models, and GHG per capita projections for each gas that reflect trends over the last decade for CO2 and follow RCP8.5 for the non-CO2 greenhouse gases.
The
FUND integrated assessment model (the ONLY model that includes benefits of warming and CO2 fertilization) gives a net social benefit of CO2 emissions of US$ 16.6 / tCO2 [21.3 - 4.3 US$ / tCO2 at 5 - 95 % CI].
In addition, the set of quantitative elements included in SSPs does not extend to outcomes such as emissions and land use that are typically calculated
by integrated assessment models, or to outcomes of impact models such as effects on agriculture.
Such impacts are consolidated
into integrated assessment models to calculate the social cost of carbon and perform global cost - benefit analyses for climate policy.
For many years, they have been based
on integrated assessment models (IAMs)-- computer models that explore the projected interplay of population, economics and energy use up to the year 2100.
Summarizing the value of all these changes into a single estimate of the social cost of carbon (SCC) requires
complex integrated assessment models that predict both environmental and economic outcomes and attach estimates of the value of those outcomes.
The requirements of plausibility and consistency have been assured by basing the RCPs on published scenarios
of integrated assessment models in the literature.
Combinations of such trends would need to be developed through a collaborative process including experts
in integrated assessment modeling, impacts and adaptation, and other relevant disciplines, with care taken to ensure the internal consistency of pathways taken as a group, keeping in mind the intended part of the space of future challenges to adaptation and mitigation to be covered.
These «
integrated assessment models» accounted for energy use, the economy, and climate and the way these different systems interact with one another.
To inform its Earth system models, the climate modeling community has a long history of using
integrated assessment models — frameworks for describing humanity's impact on Earth, including the source of global greenhouse gases, land use and land cover change, and other resource - related drivers of anthropogenic climate change.