THE 1.5°C GLOBAL WARMING TARGET AND ITS IMPACT ON FUTURE BURNED AREA IN THE BRAZILIAN SAVANNA

Patrícia S. Silva, Ana Bastos, Renata Libonati, Julia A. Rodrigues, Carlos C. DaCamara

Photo: Arthur de Magalhães Goulart/Wikimedia Commons

Cerrado: the Brazilian savanna

▪ About 20% of Brazil’s area

▪ One of the most important global biodiversity hotspots

▪ Fire-dependent biome

▪ On average, responsible for more than 50% of Brazil’s annual BA

▪ Increasingly endangered: less than 20% of its natural vegetation cover remains undisturbed

08-Apr-19 2Silva et al. 2019

The fire danger index: DSR from the FWI system

▪ The Daily Severity Rating (DSR) is a numericrating of the difficulty of controlling fires,reflecting the expected efforts required forfire suppression.

▪ Relies on daily values of:

▪ Temperature

▪ Relative Humidity

▪ Wind

▪ Precipitation

08-Apr-19 3

𝐷𝑆𝑅 = 0.0272 𝐹𝑊𝐼1.77

Source: Canadian Forest Fire Weather Index (FWI) System

Silva et al. 2019

Our data and methods

08-Apr-19 4

▪ Regional climate model: RC4 driven by EC-Earth

▪ 3 Reanalysis: ERA-Interim, MERRA-2 and JRA-55

▪ Satellite-based burned area: AQM product

▪ 3 Future climate scenarios: RCPs 2.6, 4.5 and 8.5

Silva et al. 2019

Does DSR replicate current BA in Cerrado?

08-Apr-19 5

▪ Fire season in Aug-Oct

▪ DSR satisfactorily follows BA trends

▪ Some variations not seen might be due to anthropogenic activity

▪ High R2 values between reanalysis and BA

▪ ERA-I was the best fit given its intermediate values between reanalysis and high R2

Silva et al. 2019

Development of a Burned Area Model (BAM)

08-Apr-19 6

▪ Explains 71% of the interannual variance

▪ After a leave-one-out cross validation the resulting R2 is 0.60

▪ The 10 000 generated R2

values for 𝐷𝑆𝑅𝐸𝑅𝐴−𝐼 and BA were below the 99.9 percentile

Silva et al. 2019

Does the RCM replicate past climate in Cerrado?

08-Apr-19 7

▪ Marked peak in Winter

▪ Simulated annual cycles systematically higher than observation-based

▪ Need for calibration

Silva et al. 2019

Future scenarios

08-Apr-19 8

▪ Increased BA under all scenarios

▪ Similar forcing mid-century, distinct pathways onwards

▪ In RCP 2.6, BA by the end of the century will decrease compared to mid-century

▪ For RCP 4.5 most changes will occur in the first half of the century

Silva et al. 2019

Future scenarios

08-Apr-19 9

▪ RCP 4.5 and 8.5 lead to similar increases by mid-century BA

▪ Percentiles 90 of RCP 4.5 and RCP 8.5 are considerably higher than those of RCP 2.6

▪ RCP 2.6 by end of the century did not pass the unilateral test for differences in mean at the 5% level

Silva et al. 2019

Conclusions

▪ BA can be fairly described using four climate parameters: temperature, relative humidity,

wind and precipitation

▪ The resulting BA model explains 71% of interannual BA in Cerrado

▪ Compared to historical values, future BA will increase under all climate scenarios

▪ Extreme burned area events are likely to occur with higher frequency

▪ Our results highlight the importance of keeping to the 1.5°C global warming goal by 2100

established by the UNFCCC

08-Apr-19 10Silva et al. 2019

THANK YOU!

pssilva@fc.ul.pt

FAPESP/1389/2014and 2014/20042-2

Photo: Arthur de Magalhães Goulart/Wikimedia Commons