7. The population exposure reduction target is that there is at least a 35% reduction in population exposure by the end of 31st December 2040 (“the target date”), as compared with the average population exposure in the three-year period from 1st January 2016 to 31st December 2018 (“the baseline period”), determined in accordance with regulation 8.
8.—(1) The percentage change in population exposure between the baseline period and the target date is to be measured by—
(a)determining, for each year from 2019 to 2040, the amount (in µg/m³) by which the Population Exposure Indicator for that year is greater or less than the Reference Indicator for that year;
(b)determining the sum of annual changes in population exposure between the baseline period and the target date, by adding together the amounts determined under sub-paragraph (a) for all years from 2019 to 2040; and
(c)expressing the sum of annual changes in population exposure, as represented by the amount determined under sub-paragraph (b), as a percentage of the Population Exposure Indicator for the baseline period, rounded to the nearest whole number.
(2) Schedule 1 specifies calculations which the Secretary of State is to carry out, for the purposes of enabling the determinations in paragraph (1) to be made and progress towards meeting the population exposure reduction target to be measured.
9. For the purposes of section 6(1) of the 2021 Act, the reporting date for the population exposure reduction target is 15th July 2041.
10. In this Part and in Schedule 1—
“the baseline period” has the meaning given in regulation 7;
“population exposure” means population exposure to PM2.5;
“the Population Exposure Indicator”—
for the baseline period is a measure of average population exposure in that period;
for a year from 2019 onwards is a measure of average population exposure in the three-year period ending on 31st December in that year,
calculated in accordance with Schedule 1;
“the Reference Indicator” for a year is a measure of average population exposure in the three-year period ending on 31st December in the preceding year, calculated in accordance with Schedule 1 and to be used only for the purposes of making the determination required by regulation 8(1)(a) and the calculations required by paragraphs 1(d) and 2(c) of Schedule 1.