Energia, Desenvolvimento e Meio AmbientePEN-5011

Profs José Moreira e Oswaldo Lucon, Virginia Parente e Célio Bermann

Cap. 7

Energia e meio ambiente: as causas

“Net primary production (NPP) is the difference between total photosynthesis and total respiration in an ecosystem” and is estimated by quantifying the new organic matter formed and retained by living plants in a given time (Clark et al., 2001).

Net primary productivity varies among ecosystems and depends on many factors. These include solar energy input, temperature and moisture levels, carbon dioxide levels, nutrient availability, and community interactions (e.g., grazing by herbivores)

The highest net primary productivity in terrestrial environments occurs in swamps and marshes and tropical rainforests; the lowest occurs in deserts.

The smallest land areas are occupied by tundra and temperate grassland ecosystems, and the largest land area is occupied by tropical forest. The most productive ecosystems are temperate and tropical forests, and the least productive are deserts and tundras.

In terrestrial ecosystems, NPP is measured as “mass of carbon per unit area per year” and measurement is conducted primarily through field measurements of biomass changes over time (Scurlock, Johnson, & Olson, 2002). This measurement method is limited because of logistical difficulties in measuring elements such as below ground productivity, litterfall, and herbivory, among others. In addition, different landscapes require different measurement techniques1 which complicates NPP accounting.

HANPP is the amount of this plant biomass that is diverted to humans (Garí, 1996, p. 7). Consistency in HANPP results is hampered by varying definitions of what constitutes human appropriation of NPP

Haberl (1997) defined NPP appropriation as “the difference between the NPP of the potential natural vegetation…i.e. the vegetation that would prevail if human interference were absent) and the amount of biomass currently available in ecological cycles…” (Haberl, 1997, p. 143)

Fonte: https://was-research.org/paper/an-introduction-to-human-appropriation-of-net-primary-productivity/

Fonte: https://was-research.org/paper/an-introduction-to-human-appropriation-of-net-primary-productivity/

Fonte: https://was-research.org/paper/an-introduction-to-human-appropriation-of-net-primary-productivity/

Global carbon flows related to the human appropriation of net primary production (HANPP) around the year 2000

Regional breakdown of global HANPP (excluding human-induced fires) in the year 2000

Fonte: https://was-research.org/paper/an-introduction-to-human-appropriation-of-net-primary-productivity/

HANPP =

Human

Appropriation

of NPP

NPP = Net

Present

Productivity

Global Energy Assessment, 2012

ReCiPe is a method for the impact assessment (LCIA) in a LCA. Life cycle

impact assessment (LCIA) translates emissions and resource extractions into a

limited number of environmental impact scores by means of so-called

characterisation factors.

There are two mainstream ways to derive characterisation factors, i.e. at

midpoint level and at endpoint level. ReCiPe calculates:

- 18 midpoint indicators

- 3 endpoint indicators

Midpoint indicators focus on single environmental problems, for example climate

change or acidification.

Endpoint indicators show the environmental impact on three higher aggregation

levels, being the 1) effect on human health, 2) biodiversity and 3) resource

scarcity. Converting midpoints to endpoints simplifies the interpretation of the

LCIA results. However, with each aggregation step, uncertainty in the results

increases. The figure below provides an overview of the structure of ReCiPe.

Relationship between LCI parameters (left), midpoint indicator (middle) and

endpoint indicator (right) in ReCiPe 2016.

MODELO ReCiPe – Descrição e Resultados

Captura de Carbono e Armazenamento

Os custos globais aumentam com a maior ambição da

mitigação

Disponibilidade de tecnologias tem grande influência nos

custos de mitigação

Restrições sobre o uso de tecnologias de mitigação, em particular a

Captura e Armazenagem de CO2 e a Bioenergia, podem aumentar os

custos de forma significativa

Area inundada500 km2

AreaInundada1250 km2