﻿<?xml version="1.0" encoding="utf-8"?>
<Return xmlns="http://www.irs.gov/efile" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.irs.gov/efile" returnVersion="2023v5.1">
  <ReturnHeader binaryAttachmentCnt="0">
    <ReturnTs>2024-10-07T16:54:25-05:00</ReturnTs>
    <TaxPeriodEndDt>2023-12-31</TaxPeriodEndDt>
    <PreparerFirmGrp>
      <PreparerFirmEIN>390974031</PreparerFirmEIN>
      <PreparerFirmName>
        <BusinessNameLine1Txt>WEGNER CPAS LLP</BusinessNameLine1Txt>
      </PreparerFirmName>
      <PreparerUSAddress>
        <AddressLine1Txt>230 PARK AVE FL 3</AddressLine1Txt>
        <CityNm>NEW YORK</CityNm>
        <StateAbbreviationCd>NY</StateAbbreviationCd>
        <ZIPCd>101690005</ZIPCd>
      </PreparerUSAddress>
    </PreparerFirmGrp>
    <ReturnTypeCd>990</ReturnTypeCd>
    <TaxPeriodBeginDt>2023-01-01</TaxPeriodBeginDt>
    <Filer>
      <EIN>471941171</EIN>
      <BusinessName>
        <BusinessNameLine1Txt>CLIMATE SCIENCE LEGAL DEFENSE FUND</BusinessNameLine1Txt>
      </BusinessName>
      <BusinessNameControlTxt>CLIM</BusinessNameControlTxt>
      <PhoneNum>6468010853</PhoneNum>
      <USAddress>
        <AddressLine1Txt>475 RIVERSIDE DRIVE SUITE 246</AddressLine1Txt>
        <CityNm>NEW YORK</CityNm>
        <StateAbbreviationCd>NY</StateAbbreviationCd>
        <ZIPCd>10115</ZIPCd>
      </USAddress>
    </Filer>
    <BusinessOfficerGrp>
      <PersonNm>LAUREN KURTZ</PersonNm>
      <PersonTitleTxt>EXECUTIVE DIRECTOR</PersonTitleTxt>
      <PhoneNum>6468010853</PhoneNum>
      <SignatureDt>2024-09-30</SignatureDt>
      <DiscussWithPaidPreparerInd>1</DiscussWithPaidPreparerInd>
    </BusinessOfficerGrp>
    <IRSResponsiblePrtyInfoCurrInd>0</IRSResponsiblePrtyInfoCurrInd>
    <PreparerPersonGrp>
      <PreparerPersonNm>YIGIT UCTUM CPA</PreparerPersonNm>
      <PTIN>P01269549</PTIN>
      <PhoneNum>2125511724</PhoneNum>
      <PreparationDt>2024-09-27</PreparationDt>
    </PreparerPersonGrp>
    <TaxYr>2023</TaxYr>
    <BuildTS>2024-10-15 13:58:12Z</BuildTS>
  </ReturnHeader>
  <ReturnData documentCnt="5">
    <IRS990 documentId="RetDoc1038000001" referenceDocumentId="RetDoc1044400001">
      <PrincipalOfficerNm>LAUREN KURTZ</PrincipalOfficerNm>
      <USAddress>
        <AddressLine1Txt>475 RIVERSIDE DRIVE SUITE 246</AddressLine1Txt>
        <CityNm>NEW YORK</CityNm>
        <StateAbbreviationCd>NY</StateAbbreviationCd>
        <ZIPCd>10115</ZIPCd>
      </USAddress>
      <GrossReceiptsAmt>525799</GrossReceiptsAmt>
      <GroupReturnForAffiliatesInd>0</GroupReturnForAffiliatesInd>
      <Organization501c3Ind>X</Organization501c3Ind>
      <WebsiteAddressTxt>WWW.CSLDF.ORG</WebsiteAddressTxt>
      <TypeOfOrganizationCorpInd>X</TypeOfOrganizationCorpInd>
      <FormationYr>2014</FormationYr>
      <LegalDomicileStateCd>DE</LegalDomicileStateCd>
      <ActivityOrMissionDesc>THE CLIMATE SCIENCE LEGAL DEFENSE FUND PROVIDES LEGAL ASSISTANCE TO CLIMATE RESEARCHERS, EXPERTS, AND INSTITUTIONS FACING CHALLENGES BY POLITICALLY AND IDEOLOGICALLY MOTIVATED GROUPS.</ActivityOrMissionDesc>
      <VotingMembersGoverningBodyCnt>11</VotingMembersGoverningBodyCnt>
      <VotingMembersIndependentCnt>11</VotingMembersIndependentCnt>
      <TotalEmployeeCnt>0</TotalEmployeeCnt>
      <TotalVolunteersCnt>20</TotalVolunteersCnt>
      <TotalGrossUBIAmt>0</TotalGrossUBIAmt>
      <NetUnrelatedBusTxblIncmAmt>0</NetUnrelatedBusTxblIncmAmt>
      <PYContributionsGrantsAmt>517665</PYContributionsGrantsAmt>
      <CYContributionsGrantsAmt>522694</CYContributionsGrantsAmt>
      <PYProgramServiceRevenueAmt>0</PYProgramServiceRevenueAmt>
      <CYProgramServiceRevenueAmt>0</CYProgramServiceRevenueAmt>
      <PYInvestmentIncomeAmt>582</PYInvestmentIncomeAmt>
      <CYInvestmentIncomeAmt>2810</CYInvestmentIncomeAmt>
      <PYOtherRevenueAmt>384</PYOtherRevenueAmt>
      <CYOtherRevenueAmt>295</CYOtherRevenueAmt>
      <PYTotalRevenueAmt>518631</PYTotalRevenueAmt>
      <CYTotalRevenueAmt>525799</CYTotalRevenueAmt>
      <PYGrantsAndSimilarPaidAmt>0</PYGrantsAndSimilarPaidAmt>
      <CYGrantsAndSimilarPaidAmt>0</CYGrantsAndSimilarPaidAmt>
      <PYBenefitsPaidToMembersAmt>0</PYBenefitsPaidToMembersAmt>
      <CYBenefitsPaidToMembersAmt>0</CYBenefitsPaidToMembersAmt>
      <PYSalariesCompEmpBnftPaidAmt>191932</PYSalariesCompEmpBnftPaidAmt>
      <CYSalariesCompEmpBnftPaidAmt>168139</CYSalariesCompEmpBnftPaidAmt>
      <PYTotalProfFndrsngExpnsAmt>0</PYTotalProfFndrsngExpnsAmt>
      <CYTotalProfFndrsngExpnsAmt>0</CYTotalProfFndrsngExpnsAmt>
      <CYTotalFundraisingExpenseAmt>74796</CYTotalFundraisingExpenseAmt>
      <PYOtherExpensesAmt>174779</PYOtherExpensesAmt>
      <CYOtherExpensesAmt>198872</CYOtherExpensesAmt>
      <PYTotalExpensesAmt>366711</PYTotalExpensesAmt>
      <CYTotalExpensesAmt>367011</CYTotalExpensesAmt>
      <PYRevenuesLessExpensesAmt>151920</PYRevenuesLessExpensesAmt>
      <CYRevenuesLessExpensesAmt>158788</CYRevenuesLessExpensesAmt>
      <TotalAssetsBOYAmt>1087317</TotalAssetsBOYAmt>
      <TotalAssetsEOYAmt>1243468</TotalAssetsEOYAmt>
      <TotalLiabilitiesBOYAmt>26167</TotalLiabilitiesBOYAmt>
      <TotalLiabilitiesEOYAmt>23530</TotalLiabilitiesEOYAmt>
      <NetAssetsOrFundBalancesBOYAmt>1061150</NetAssetsOrFundBalancesBOYAmt>
      <NetAssetsOrFundBalancesEOYAmt>1219938</NetAssetsOrFundBalancesEOYAmt>
      <InfoInScheduleOPartIIIInd>X</InfoInScheduleOPartIIIInd>
      <MissionDesc>SEE SCHEDULE OTHE CLIMATE SCIENCE LEGAL DEFENSE FUND (CSLDF) PROTECTS THE SCIENTIFIC ENDEAVOR BY PUTTING OUR LEGAL EXPERTISE TO WORK FOR SCIENTISTS WHO ARE THREATENED OR SILENCED FOR DOING THEIR JOBS. OUR EFFORTS AND EDUCATIONAL RESOURCES PRESERVE AND EXPAND SCIENTISTS' RIGHTS AND STRENGTHEN LEGAL PROTECTIONS TO PROMOTE SCIENTIFIC INTEGRITY.</MissionDesc>
      <SignificantNewProgramSrvcInd>0</SignificantNewProgramSrvcInd>
      <SignificantChangeInd>0</SignificantChangeInd>
      <ExpenseAmt>209956</ExpenseAmt>
      <GrantAmt>0</GrantAmt>
      <RevenueAmt>0</RevenueAmt>
      <Desc>THE CLIMATE SCIENCE LEGAL DEFENSE FUND WORKS TO EDUCATE THE SCIENTIFIC COMMUNITY ABOUT THEIR RIGHTS AND THEIR RESPONSIBILITIES REGARDING LEGAL ISSUES SURROUNDING THEIR WORK, AS WELL AS EDUCATE THE PUBLIC ON LEGAL ISSUES FACING SCIENTISTS. CSLDF ALSO SERVES AS A CLEARINGHOUSE FOR INFORMATION RELATED TO LEGAL ACTIONS TAKEN AGAINST SCIENTISTS IN ORDER TO PROVIDE LAWYERS REPRESENTING SCIENTISTS WITH INFORMATION ABOUT PAST CASES AND STRATEGIES. THE CLIMATE SCIENCE LEGAL DEFENSE FUND TAKES AN ACTIVE INTEREST IN LITIGATION INVOLVING SCIENTISTS, INCLUDING HELPING RAISE FUNDS FOR SCIENTISTS' DEFENSE, SERVING AS A RESOURCE IN FINDING PRO BONO REPRESENTATION, FILING COURT PAPERS URGING THE PROTECTION OF SCIENCE AND SCIENTISTS, AND PROVIDING SUPPORT DURING DIFFICULT LITIGATION OR THREATENED LITIGATION.</Desc>
      <TotalProgramServiceExpensesAmt>209956</TotalProgramServiceExpensesAmt>
      <DescribedInSection501c3Ind referenceDocumentId="RetDoc1039100001">1</DescribedInSection501c3Ind>
      <ScheduleBRequiredInd referenceDocumentId="RetDoc1234500001">1</ScheduleBRequiredInd>
      <PoliticalCampaignActyInd>0</PoliticalCampaignActyInd>
      <LobbyingActivitiesInd>0</LobbyingActivitiesInd>
      <SubjectToProxyTaxInd>0</SubjectToProxyTaxInd>
      <DonorAdvisedFundInd referenceDocumentId="RetDoc1040000001">0</DonorAdvisedFundInd>
      <ConservationEasementsInd referenceDocumentId="RetDoc1040000001">0</ConservationEasementsInd>
      <CollectionsOfArtInd referenceDocumentId="RetDoc1040000001">0</CollectionsOfArtInd>
      <CreditCounselingInd referenceDocumentId="RetDoc1040000001">0</CreditCounselingInd>
      <DonorRstrOrQuasiEndowmentsInd>0</DonorRstrOrQuasiEndowmentsInd>
      <ReportLandBuildingEquipmentInd referenceDocumentId="RetDoc1040000001">1</ReportLandBuildingEquipmentInd>
      <ReportInvestmentsOtherSecInd referenceDocumentId="RetDoc1040000001">0</ReportInvestmentsOtherSecInd>
      <ReportProgramRelatedInvstInd referenceDocumentId="RetDoc1040000001">0</ReportProgramRelatedInvstInd>
      <ReportOtherAssetsInd referenceDocumentId="RetDoc1040000001">0</ReportOtherAssetsInd>
      <ReportOtherLiabilitiesInd referenceDocumentId="RetDoc1040000001">0</ReportOtherLiabilitiesInd>
      <IncludeFIN48FootnoteInd referenceDocumentId="RetDoc1040000001">0</IncludeFIN48FootnoteInd>
      <IndependentAuditFinclStmtInd referenceDocumentId="RetDoc1040000001">1</IndependentAuditFinclStmtInd>
      <ConsolidatedAuditFinclStmtInd referenceDocumentId="RetDoc1040000001">0</ConsolidatedAuditFinclStmtInd>
      <SchoolOperatingInd>0</SchoolOperatingInd>
      <ForeignOfficeInd>0</ForeignOfficeInd>
      <ForeignActivitiesInd>0</ForeignActivitiesInd>
      <MoreThan5000KToOrgInd>0</MoreThan5000KToOrgInd>
      <MoreThan5000KToIndividualsInd>0</MoreThan5000KToIndividualsInd>
      <ProfessionalFundraisingInd>0</ProfessionalFundraisingInd>
      <FundraisingActivitiesInd>0</FundraisingActivitiesInd>
      <GamingActivitiesInd>0</GamingActivitiesInd>
      <OperateHospitalInd>0</OperateHospitalInd>
      <GrantsToOrganizationsInd>0</GrantsToOrganizationsInd>
      <GrantsToIndividualsInd>0</GrantsToIndividualsInd>
      <ScheduleJRequiredInd>0</ScheduleJRequiredInd>
      <TaxExemptBondsInd>0</TaxExemptBondsInd>
      <EngagedInExcessBenefitTransInd>0</EngagedInExcessBenefitTransInd>
      <PYExcessBenefitTransInd>0</PYExcessBenefitTransInd>
      <LoanOutstandingInd>0</LoanOutstandingInd>
      <GrantToRelatedPersonInd>0</GrantToRelatedPersonInd>
      <BusinessRlnWithOrgMemInd>0</BusinessRlnWithOrgMemInd>
      <BusinessRlnWithFamMemInd>0</BusinessRlnWithFamMemInd>
      <BusinessRlnWith35CtrlEntInd>0</BusinessRlnWith35CtrlEntInd>
      <DeductibleNonCashContriInd>0</DeductibleNonCashContriInd>
      <DeductibleArtContributionInd>0</DeductibleArtContributionInd>
      <TerminateOperationsInd>0</TerminateOperationsInd>
      <PartialLiquidationInd>0</PartialLiquidationInd>
      <DisregardedEntityInd>0</DisregardedEntityInd>
      <RelatedEntityInd>0</RelatedEntityInd>
      <RelatedOrganizationCtrlEntInd>0</RelatedOrganizationCtrlEntInd>
      <TrnsfrExmptNonChrtblRltdOrgInd>0</TrnsfrExmptNonChrtblRltdOrgInd>
      <ActivitiesConductedPrtshpInd>0</ActivitiesConductedPrtshpInd>
      <ScheduleORequiredInd>1</ScheduleORequiredInd>
      <IRPDocumentCnt>9</IRPDocumentCnt>
      <IRPDocumentW2GCnt>0</IRPDocumentW2GCnt>
      <EmployeeCnt>0</EmployeeCnt>
      <UnrelatedBusIncmOverLimitInd>0</UnrelatedBusIncmOverLimitInd>
      <ForeignFinancialAccountInd>0</ForeignFinancialAccountInd>
      <ProhibitedTaxShelterTransInd>0</ProhibitedTaxShelterTransInd>
      <TaxablePartyNotificationInd>0</TaxablePartyNotificationInd>
      <NondeductibleContributionsInd>0</NondeductibleContributionsInd>
      <QuidProQuoContributionsInd>0</QuidProQuoContributionsInd>
      <Form8282PropertyDisposedOfInd>0</Form8282PropertyDisposedOfInd>
      <RcvFndsToPayPrsnlBnftCntrctInd>0</RcvFndsToPayPrsnlBnftCntrctInd>
      <PayPremiumsPrsnlBnftCntrctInd>0</PayPremiumsPrsnlBnftCntrctInd>
      <IndoorTanningServicesInd>0</IndoorTanningServicesInd>
      <SubjToTaxRmnrtnExPrchtPymtInd>0</SubjToTaxRmnrtnExPrchtPymtInd>
      <SubjectToExcsTaxNetInvstIncInd>0</SubjectToExcsTaxNetInvstIncInd>
      <InfoInScheduleOPartVIInd>X</InfoInScheduleOPartVIInd>
      <GoverningBodyVotingMembersCnt>11</GoverningBodyVotingMembersCnt>
      <IndependentVotingMemberCnt>11</IndependentVotingMemberCnt>
      <FamilyOrBusinessRlnInd>0</FamilyOrBusinessRlnInd>
      <DelegationOfMgmtDutiesInd>0</DelegationOfMgmtDutiesInd>
      <ChangeToOrgDocumentsInd>0</ChangeToOrgDocumentsInd>
      <MaterialDiversionOrMisuseInd>0</MaterialDiversionOrMisuseInd>
      <MembersOrStockholdersInd>0</MembersOrStockholdersInd>
      <ElectionOfBoardMembersInd>0</ElectionOfBoardMembersInd>
      <DecisionsSubjectToApprovaInd>0</DecisionsSubjectToApprovaInd>
      <MinutesOfGoverningBodyInd>1</MinutesOfGoverningBodyInd>
      <MinutesOfCommitteesInd>1</MinutesOfCommitteesInd>
      <OfficerMailingAddressInd>0</OfficerMailingAddressInd>
      <LocalChaptersInd>0</LocalChaptersInd>
      <Form990ProvidedToGvrnBodyInd>1</Form990ProvidedToGvrnBodyInd>
      <ConflictOfInterestPolicyInd>1</ConflictOfInterestPolicyInd>
      <AnnualDisclosureCoveredPrsnInd>1</AnnualDisclosureCoveredPrsnInd>
      <RegularMonitoringEnfrcInd>1</RegularMonitoringEnfrcInd>
      <WhistleblowerPolicyInd>1</WhistleblowerPolicyInd>
      <DocumentRetentionPolicyInd>1</DocumentRetentionPolicyInd>
      <CompensationProcessCEOInd>1</CompensationProcessCEOInd>
      <CompensationProcessOtherInd>0</CompensationProcessOtherInd>
      <InvestmentInJointVentureInd>0</InvestmentInJointVentureInd>
      <StatesWhereCopyOfReturnIsFldCd>CA</StatesWhereCopyOfReturnIsFldCd>
      <StatesWhereCopyOfReturnIsFldCd>FL</StatesWhereCopyOfReturnIsFldCd>
      <StatesWhereCopyOfReturnIsFldCd>MA</StatesWhereCopyOfReturnIsFldCd>
      <StatesWhereCopyOfReturnIsFldCd>MD</StatesWhereCopyOfReturnIsFldCd>
      <StatesWhereCopyOfReturnIsFldCd>MI</StatesWhereCopyOfReturnIsFldCd>
      <StatesWhereCopyOfReturnIsFldCd>NC</StatesWhereCopyOfReturnIsFldCd>
      <StatesWhereCopyOfReturnIsFldCd>NH</StatesWhereCopyOfReturnIsFldCd>
      <StatesWhereCopyOfReturnIsFldCd>NY</StatesWhereCopyOfReturnIsFldCd>
      <StatesWhereCopyOfReturnIsFldCd>OR</StatesWhereCopyOfReturnIsFldCd>
      <StatesWhereCopyOfReturnIsFldCd>PA</StatesWhereCopyOfReturnIsFldCd>
      <StatesWhereCopyOfReturnIsFldCd>VA</StatesWhereCopyOfReturnIsFldCd>
      <OwnWebsiteInd>X</OwnWebsiteInd>
      <UponRequestInd>X</UponRequestInd>
      <BooksInCareOfDetail>
        <PersonNm>LAUREN KURTZ</PersonNm>
        <PhoneNum>6468010853</PhoneNum>
        <USAddress>
          <AddressLine1Txt>475 RIVERSIDE DR STE 246</AddressLine1Txt>
          <CityNm>NEW YORK</CityNm>
          <StateAbbreviationCd>NY</StateAbbreviationCd>
          <ZIPCd>10115</ZIPCd>
        </USAddress>
      </BooksInCareOfDetail>
      <Form990PartVIISectionAGrp>
        <PersonNm>JOSHUA WOLFE</PersonNm>
        <TitleTxt>PRESIDENT</TitleTxt>
        <AverageHoursPerWeekRt>5.00</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <OfficerInd>X</OfficerInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>SCOTT MANDIA</PersonNm>
        <TitleTxt>SECRETARY</TitleTxt>
        <AverageHoursPerWeekRt>1.00</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <OfficerInd>X</OfficerInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>CHARLES ZELLER</PersonNm>
        <TitleTxt>TREASURER</TitleTxt>
        <AverageHoursPerWeekRt>2.00</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <OfficerInd>X</OfficerInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>ANDREW FREY</PersonNm>
        <TitleTxt>VICE PRESIDENT</TitleTxt>
        <AverageHoursPerWeekRt>2.00</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <OfficerInd>X</OfficerInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>NAOMI ORESKES</PersonNm>
        <TitleTxt>DIRECTOR</TitleTxt>
        <AverageHoursPerWeekRt>1.00</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>JEFFREY MASTERS</PersonNm>
        <TitleTxt>DIRECTOR</TitleTxt>
        <AverageHoursPerWeekRt>2.00</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>MICHAEL OPPENHEIMER</PersonNm>
        <TitleTxt>DIRECTOR</TitleTxt>
        <AverageHoursPerWeekRt>1.00</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>MICHAEL GERRARD</PersonNm>
        <TitleTxt>DIRECTOR</TitleTxt>
        <AverageHoursPerWeekRt>1.00</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>KATRINA KUH</PersonNm>
        <TitleTxt>DIRECTOR</TitleTxt>
        <AverageHoursPerWeekRt>1.00</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>CYMIE PAYNE</PersonNm>
        <TitleTxt>DIRECTOR</TitleTxt>
        <AverageHoursPerWeekRt>1.00</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>ARADHNA TRIPATI</PersonNm>
        <TitleTxt>DIRECTOR</TitleTxt>
        <AverageHoursPerWeekRt>1.00</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>LAUREN KURTZ</PersonNm>
        <TitleTxt>EXECUTIVE DIRECTOR</TitleTxt>
        <AverageHoursPerWeekRt>40.00</AverageHoursPerWeekRt>
        <OfficerInd>X</OfficerInd>
        <ReportableCompFromOrgAmt>88000</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>69</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <TotalReportableCompFromOrgAmt>88000</TotalReportableCompFromOrgAmt>
      <TotReportableCompRltdOrgAmt>0</TotReportableCompRltdOrgAmt>
      <TotalOtherCompensationAmt>69</TotalOtherCompensationAmt>
      <IndivRcvdGreaterThan100KCnt>0</IndivRcvdGreaterThan100KCnt>
      <FormerOfcrEmployeesListedInd>0</FormerOfcrEmployeesListedInd>
      <TotalCompGreaterThan150KInd>0</TotalCompGreaterThan150KInd>
      <CompensationFromOtherSrcsInd>0</CompensationFromOtherSrcsInd>
      <CntrctRcvdGreaterThan100KCnt>0</CntrctRcvdGreaterThan100KCnt>
      <AllOtherContributionsAmt>522694</AllOtherContributionsAmt>
      <TotalContributionsAmt>522694</TotalContributionsAmt>
      <InvestmentIncomeGrp>
        <TotalRevenueColumnAmt>2810</TotalRevenueColumnAmt>
        <ExclusionAmt>2810</ExclusionAmt>
      </InvestmentIncomeGrp>
      <MiscellaneousRevenueGrp>
        <TotalRevenueColumnAmt>295</TotalRevenueColumnAmt>
        <ExclusionAmt>295</ExclusionAmt>
      </MiscellaneousRevenueGrp>
      <OtherRevenueTotalAmt>295</OtherRevenueTotalAmt>
      <TotalRevenueGrp>
        <TotalRevenueColumnAmt>525799</TotalRevenueColumnAmt>
        <RelatedOrExemptFuncIncomeAmt>0</RelatedOrExemptFuncIncomeAmt>
        <UnrelatedBusinessRevenueAmt>0</UnrelatedBusinessRevenueAmt>
        <ExclusionAmt>3105</ExclusionAmt>
      </TotalRevenueGrp>
      <InfoInScheduleOPartIXInd>X</InfoInScheduleOPartIXInd>
      <CompCurrentOfcrDirectorsGrp>
        <TotalAmt>88069</TotalAmt>
        <ProgramServicesAmt>74859</ProgramServicesAmt>
        <ManagementAndGeneralAmt>6605</ManagementAndGeneralAmt>
        <FundraisingAmt>6605</FundraisingAmt>
      </CompCurrentOfcrDirectorsGrp>
      <OtherSalariesAndWagesGrp>
        <TotalAmt>56090</TotalAmt>
        <ProgramServicesAmt>52964</ProgramServicesAmt>
        <ManagementAndGeneralAmt>461</ManagementAndGeneralAmt>
        <FundraisingAmt>2665</FundraisingAmt>
      </OtherSalariesAndWagesGrp>
      <OtherEmployeeBenefitsGrp>
        <TotalAmt>10419</TotalAmt>
        <ProgramServicesAmt>10330</ProgramServicesAmt>
        <ManagementAndGeneralAmt>39</ManagementAndGeneralAmt>
        <FundraisingAmt>50</FundraisingAmt>
      </OtherEmployeeBenefitsGrp>
      <PayrollTaxesGrp>
        <TotalAmt>13561</TotalAmt>
        <ProgramServicesAmt>12024</ProgramServicesAmt>
        <ManagementAndGeneralAmt>669</ManagementAndGeneralAmt>
        <FundraisingAmt>868</FundraisingAmt>
      </PayrollTaxesGrp>
      <FeesForServicesAccountingGrp>
        <TotalAmt>12850</TotalAmt>
        <ManagementAndGeneralAmt>12850</ManagementAndGeneralAmt>
      </FeesForServicesAccountingGrp>
      <FeesForServicesOtherGrp>
        <TotalAmt>117936</TotalAmt>
        <ProgramServicesAmt>28830</ProgramServicesAmt>
        <ManagementAndGeneralAmt>33160</ManagementAndGeneralAmt>
        <FundraisingAmt>55946</FundraisingAmt>
      </FeesForServicesOtherGrp>
      <AdvertisingGrp>
        <TotalAmt>1653</TotalAmt>
        <ProgramServicesAmt>1106</ProgramServicesAmt>
        <ManagementAndGeneralAmt>475</ManagementAndGeneralAmt>
        <FundraisingAmt>72</FundraisingAmt>
      </AdvertisingGrp>
      <OfficeExpensesGrp>
        <TotalAmt>14039</TotalAmt>
        <ProgramServicesAmt>857</ProgramServicesAmt>
        <ManagementAndGeneralAmt>8534</ManagementAndGeneralAmt>
        <FundraisingAmt>4648</FundraisingAmt>
      </OfficeExpensesGrp>
      <InformationTechnologyGrp>
        <TotalAmt>5796</TotalAmt>
        <ProgramServicesAmt>2974</ProgramServicesAmt>
        <ManagementAndGeneralAmt>148</ManagementAndGeneralAmt>
        <FundraisingAmt>2674</FundraisingAmt>
      </InformationTechnologyGrp>
      <OccupancyGrp>
        <TotalAmt>19657</TotalAmt>
        <ProgramServicesAmt>17436</ProgramServicesAmt>
        <ManagementAndGeneralAmt>963</ManagementAndGeneralAmt>
        <FundraisingAmt>1258</FundraisingAmt>
      </OccupancyGrp>
      <TravelGrp>
        <TotalAmt>10</TotalAmt>
        <FundraisingAmt>10</FundraisingAmt>
      </TravelGrp>
      <ConferencesMeetingsGrp>
        <TotalAmt>3576</TotalAmt>
        <ProgramServicesAmt>3576</ProgramServicesAmt>
      </ConferencesMeetingsGrp>
      <DepreciationDepletionGrp>
        <TotalAmt>2966</TotalAmt>
        <ManagementAndGeneralAmt>2966</ManagementAndGeneralAmt>
      </DepreciationDepletionGrp>
      <InsuranceGrp>
        <TotalAmt>20389</TotalAmt>
        <ProgramServicesAmt>5000</ProgramServicesAmt>
        <ManagementAndGeneralAmt>15389</ManagementAndGeneralAmt>
      </InsuranceGrp>
      <TotalFunctionalExpensesGrp>
        <TotalAmt>367011</TotalAmt>
        <ProgramServicesAmt>209956</ProgramServicesAmt>
        <ManagementAndGeneralAmt>82259</ManagementAndGeneralAmt>
        <FundraisingAmt>74796</FundraisingAmt>
      </TotalFunctionalExpensesGrp>
      <CashNonInterestBearingGrp>
        <BOYAmt>781560</BOYAmt>
        <EOYAmt>865346</EOYAmt>
      </CashNonInterestBearingGrp>
      <SavingsAndTempCashInvstGrp>
        <BOYAmt>279699</BOYAmt>
        <EOYAmt>282509</EOYAmt>
      </SavingsAndTempCashInvstGrp>
      <PledgesAndGrantsReceivableGrp>
        <BOYAmt>1449</BOYAmt>
        <EOYAmt>76181</EOYAmt>
      </PledgesAndGrantsReceivableGrp>
      <PrepaidExpensesDefrdChargesGrp>
        <BOYAmt>18918</BOYAmt>
        <EOYAmt>16707</EOYAmt>
      </PrepaidExpensesDefrdChargesGrp>
      <LandBldgEquipCostOrOtherBssAmt>24248</LandBldgEquipCostOrOtherBssAmt>
      <LandBldgEquipAccumDeprecAmt>23553</LandBldgEquipAccumDeprecAmt>
      <LandBldgEquipBasisNetGrp>
        <BOYAmt>3661</BOYAmt>
        <EOYAmt>695</EOYAmt>
      </LandBldgEquipBasisNetGrp>
      <OtherAssetsTotalGrp>
        <BOYAmt>2030</BOYAmt>
        <EOYAmt>2030</EOYAmt>
      </OtherAssetsTotalGrp>
      <TotalAssetsGrp>
        <BOYAmt>1087317</BOYAmt>
        <EOYAmt>1243468</EOYAmt>
      </TotalAssetsGrp>
      <AccountsPayableAccrExpnssGrp>
        <BOYAmt>26167</BOYAmt>
        <EOYAmt>23530</EOYAmt>
      </AccountsPayableAccrExpnssGrp>
      <TotalLiabilitiesGrp>
        <BOYAmt>26167</BOYAmt>
        <EOYAmt>23530</EOYAmt>
      </TotalLiabilitiesGrp>
      <OrganizationFollowsFASB117Ind>X</OrganizationFollowsFASB117Ind>
      <NoDonorRestrictionNetAssetsGrp>
        <BOYAmt>1061150</BOYAmt>
        <EOYAmt>1159938</EOYAmt>
      </NoDonorRestrictionNetAssetsGrp>
      <DonorRestrictionNetAssetsGrp>
        <BOYAmt>0</BOYAmt>
        <EOYAmt>60000</EOYAmt>
      </DonorRestrictionNetAssetsGrp>
      <TotalNetAssetsFundBalanceGrp>
        <BOYAmt>1061150</BOYAmt>
        <EOYAmt>1219938</EOYAmt>
      </TotalNetAssetsFundBalanceGrp>
      <TotLiabNetAssetsFundBalanceGrp>
        <BOYAmt>1087317</BOYAmt>
        <EOYAmt>1243468</EOYAmt>
      </TotLiabNetAssetsFundBalanceGrp>
      <ReconcilationRevenueExpnssAmt>158788</ReconcilationRevenueExpnssAmt>
      <OtherChangesInNetAssetsAmt>0</OtherChangesInNetAssetsAmt>
      <InfoInScheduleOPartXIIInd>X</InfoInScheduleOPartXIIInd>
      <MethodOfAccountingAccrualInd>X</MethodOfAccountingAccrualInd>
      <AccountantCompileOrReviewInd>0</AccountantCompileOrReviewInd>
      <FSAuditedInd>1</FSAuditedInd>
      <FSAuditedBasisGrp>
        <SeparateBasisFinclStmtInd>X</SeparateBasisFinclStmtInd>
      </FSAuditedBasisGrp>
      <AuditCommitteeInd>1</AuditCommitteeInd>
      <FederalGrantAuditRequiredInd>0</FederalGrantAuditRequiredInd>
    </IRS990>
    <IRS990ScheduleA documentId="RetDoc1039100001">
      <PublicOrganization170Ind>X</PublicOrganization170Ind>
      <GiftsGrantsContriRcvd170Grp>
        <CurrentTaxYearMinus4YearsAmt>502800</CurrentTaxYearMinus4YearsAmt>
        <CurrentTaxYearMinus3YearsAmt>357913</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>569124</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>517665</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>522694</CurrentTaxYearAmt>
        <TotalAmt>2470196</TotalAmt>
      </GiftsGrantsContriRcvd170Grp>
      <TotalCalendarYear170Grp>
        <CurrentTaxYearMinus4YearsAmt>502800</CurrentTaxYearMinus4YearsAmt>
        <CurrentTaxYearMinus3YearsAmt>357913</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>569124</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>517665</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>522694</CurrentTaxYearAmt>
        <TotalAmt>2470196</TotalAmt>
      </TotalCalendarYear170Grp>
      <SubstantialContributorsTotAmt>528868</SubstantialContributorsTotAmt>
      <PublicSupportTotal170Amt>1941328</PublicSupportTotal170Amt>
      <GrossInvestmentIncome170Grp>
        <CurrentTaxYearMinus3YearsAmt>2960</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>1157</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>582</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>2810</CurrentTaxYearAmt>
        <TotalAmt>7509</TotalAmt>
      </GrossInvestmentIncome170Grp>
      <TotalSupportAmt>2477705</TotalSupportAmt>
      <GrossReceiptsRltdActivitiesAmt>9906</GrossReceiptsRltdActivitiesAmt>
      <PublicSupportCY170Pct>0.78350</PublicSupportCY170Pct>
      <PublicSupportPY170Pct>0.74940</PublicSupportPY170Pct>
      <ThirtyThrPctSuprtTestsCY170Ind>X</ThirtyThrPctSuprtTestsCY170Ind>
    </IRS990ScheduleA>
    <IRS990ScheduleB documentId="RetDoc1234500001">
      <ContributorInformationGrp>
        <ContributorNum>RESTRICTED</ContributorNum>
        <ContributorBusinessName>
          <BusinessNameLine1>RESTRICTED</BusinessNameLine1>
        </ContributorBusinessName>
        <ContributorUSAddress>
          <AddressLine1>RESTRICTED</AddressLine1>
          <AddressLine2>RESTRICTED</AddressLine2>
          <City>RESTRICTED</City>
          <State>RESTRICTED</State>
          <ZIPCode>RESTRICTED</ZIPCode>
        </ContributorUSAddress>
        <TotalContributionsAmt>RESTRICTED</TotalContributionsAmt>
      </ContributorInformationGrp>
    </IRS990ScheduleB>
    <IRS990ScheduleD documentId="RetDoc1040000001">
      <EquipmentGrp>
        <OtherCostOrOtherBasisAmt>5498</OtherCostOrOtherBasisAmt>
        <DepreciationAmt>4803</DepreciationAmt>
        <BookValueAmt>695</BookValueAmt>
      </EquipmentGrp>
      <OtherLandBuildingsGrp>
        <OtherCostOrOtherBasisAmt>18750</OtherCostOrOtherBasisAmt>
        <DepreciationAmt>18750</DepreciationAmt>
        <BookValueAmt>0</BookValueAmt>
      </OtherLandBuildingsGrp>
      <TotalBookValueLandBuildingsAmt>695</TotalBookValueLandBuildingsAmt>
      <TotalRevEtcAuditedFinclStmtAmt>625615</TotalRevEtcAuditedFinclStmtAmt>
      <DonatedServicesAndUseFcltsAmt>99816</DonatedServicesAndUseFcltsAmt>
      <RevenueNotReportedAmt>99816</RevenueNotReportedAmt>
      <RevenueSubtotalAmt>525799</RevenueSubtotalAmt>
      <RevenueNotReportedFinclStmtAmt>0</RevenueNotReportedFinclStmtAmt>
      <TotalRevenuePerForm990Amt>525799</TotalRevenuePerForm990Amt>
      <TotExpnsEtcAuditedFinclStmtAmt>466827</TotExpnsEtcAuditedFinclStmtAmt>
      <DonatedServicesUseFcltsAmt>99816</DonatedServicesUseFcltsAmt>
      <ExpensesNotReportedAmt>99816</ExpensesNotReportedAmt>
      <ExpensesSubtotalAmt>367011</ExpensesSubtotalAmt>
      <ExpensesNotRptFinclStmtAmt>0</ExpensesNotRptFinclStmtAmt>
      <TotalExpensesPerForm990Amt>367011</TotalExpensesPerForm990Amt>
    </IRS990ScheduleD>
    <IRS990ScheduleO documentId="RetDoc1044400001">
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PART VI, SECTION B, LINE 11B</FormAndLineReferenceDesc>
        <ExplanationTxt>THE PREPARED FORM 990 IS REVIEWED BY THE ORGANIZATION'S GOVERNING BODY BEFORE THE RETURN IS FILED WITH THE IRS.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PART VI, SECTION B, LINE 12C</FormAndLineReferenceDesc>
        <ExplanationTxt>ANNUALLY ALL DIRECTORS AND OFFICERS COMPLETE AND SIGN A STATEMENT THAT PROVIDES INFORMATION REGARDING THEIR INTERESTS AND THOSE OF THEIR FAMILY MEMBERS THAT COULD GIVE RISE TO CONFLICTS. THE MEMBERS OF THE GOVERNING BODY MAKE DETERMINATIONS OF WHETHER A CONFLICT EXISTS AND REVIEW ACTUAL CONFLICTS. ANY PERSON WITH A CONFLICT IS PROHIBITED FROM PARTICIPATING IN THE GOVERNING BODY'S DELIBERATIONS AND DECISIONS IN THE TRANSACTION.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PART VI, SECTION B, LINE 15A</FormAndLineReferenceDesc>
        <ExplanationTxt>COMPENSATION FOR MANAGEMENT PERSONNEL IS COMPARED TO THE INDUSTRY STANDARDS OF SIMILAR ORGANIZATION'S UPON FIRST HIRING. ALL SUBSEQUENT RAISES ARE REVIEWED AND APPROVED BY THE BOARD OF DIRECTORS. THE BOARD INCORPORATES THE OVERALL FINANCIAL HEALTH OF THE ORGANIZATION INTO THEIR DECISION MAKING.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PART VI, SECTION C, LINE 19</FormAndLineReferenceDesc>
        <ExplanationTxt>THE ORGANIZATION MAKES ITS GOVERNING DOCUMENTS, CONFLICT OF INTEREST POLICY, AND FINANCIAL STATEMENTS AVAILABLE TO THE PUBLIC UPON REQUEST.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PART IX, LINE 11G</FormAndLineReferenceDesc>
        <ExplanationTxt>CONSULTANTS: PROGRAM SERVICE EXPENSES 28,830. MANAGEMENT AND GENERAL EXPENSES 19,607. FUNDRAISING EXPENSES 55,946. TOTAL EXPENSES 104,383. PAYROLL PROCESSING FEES: PROGRAM SERVICE EXPENSES 0. MANAGEMENT AND GENERAL EXPENSES 13,553. FUNDRAISING EXPENSES 0. TOTAL EXPENSES 13,553.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PART V, LINE 2A, PROFESSIONAL EMPLOYMENT ORGANIZATION</FormAndLineReferenceDesc>
        <ExplanationTxt>CLIMATE SCIENCE MAINTAINS A CO-EMPLOYMENT AGREEMENT WITH TRINET, A PROFESSIONAL EMPLOYER ORGANIZATION (PEO), PROVIDING OUTSOURCED HUMAN RESOURCES AND EMPLOYER SERVICES. IN THIS ARRANGEMENT, THE EMPLOYEES ARE CONSIDERED COMMON LAW EMPLOYEES OF CLIMATE SCIENCE, HOWEVER, TRINET IS THE EMPLOYER OF RECORD, PAYROLL, BENEFITS, AND OTHER FUNCTIONS INVOLVING EMPLOYER-RELATED ADMINISTRATION.</ExplanationTxt>
      </SupplementalInformationDetail>
    </IRS990ScheduleO>
  </ReturnData>
</Return>